I didn’t hear rave reviews about Big Sur either but it has been incredibly stable for me with the exception of iCloud Drive (which has been a problem for years apparently and I have finally completely abandoned). Monterey was a disaster on my iMac so I rolled it back to Big Sur for the time being.
EDIT: Not enough brain power to distinguish between Catalina and Monterey apparently... thanks @ccstone 
Forward you mean? 
HAHA! Yea.... I meant Monterey... it's been a long day
Sounds like moving windows around with Keyboard Maestro is the absolute least of your problems. To be honest I’m amazed the Macro runs at all with all that other stuff going on 
With all the problems you’ve listed it sounds like you must have reached the end of any road of annoyances. But forgetting about mending any of that for a moment - I have one bit of advice for you:
Make your next project to methodically back up all your Photos and Data and Contact Addresses and emails and Photoshop Templates and Keyboard Maestro Macros and Excel or Numbers Spreadsheets and Passwords etc etc onto external hard disks. And keep thinking of anything else you might need to back up - imagining that your MacBook Air was run over by a truck and you suddenly hadn’t got any Mac at all and had to start from scratch.
And I don’t count Time Machine as a backup in this sense. It’s still a proprietary Mac file that could get corrupted. I mean manually copying files and folders.
And this is a real project that will take more than one day and involve ticking off things on an actual pen and paper list. (In other words - it’s the really fun sort of computer task where you’re doing something fairly simple but it counts as important work 
).
And regarding the Mac Photos Library. As well as making a backup of the Photos Library File I make sure I have copies of the original Photo Files saved outside of the Photos Library itself. Digital Photos and Home Videos are one of the most precious kinds of data, as they are unique moments in time that are impossible to recreate if they are lost. (The simplest way to back them up is to use the Photos "export originals" menu option and save them direct to an external hard drive - make sure to have Photos "use original name" for the export otherwise the exported versions will have long meaningless numbers as their names.)
After you’ve backed up everything - make exact copies of those backup hard drives and give those copies to a friend so there are copies away from your house.
Don’t do any more tinkering until you have at least 1) The complete backup of everything that is unique to you and preferably, 2) a brand new unused Mac to start fresh on.
When you get another new Mac don’t initially change any of its default settings. Sign into iCloud. Let that copy over your addresses and email settings.
Then manually reinstall your third party software and manually copy over your data. (I’ve never used Migration Assistant.) That way you are not copying over the problems that you are experiencing on your current Mac onto your new Mac. Once you are happy the new Mac is working fine and there is no data remaining on your old MacBook Air - you can wipe the MacBook Air and treat it like a new Mac and hopefully leave all the problems you have listed behind. And - best of all - your Keyboard Maestro Macro should happily maximise any window in one instant step 
Moving forward:
I have come to rely on a lot of Cloud based syncing Apps - iCloud Calendars/Contacts, Dropbox, iCloud Photos and as of now they are all working and making my life easier. It sounds like you have been very unlucky - Migration Assistant (although I haven’t ever used it) should work and not cause the problems you are experiencing.
I've had the same issue in the past, multiple times, randomly appeared.
I've had issues with resizing MS Word to half screen with KM. I switched to BetterTouchTool for this purpose, which works more reliably. (It's great to have alternative apps.)
Also, sometimes, as I move the mouse, the window changes its size (without pressing any keys). I have set ⌘⌥⌃+Mouse Move to resize window in BetterTouchTool. But I was not pressing any modifier keys. Maybe this is an issue with BTT and not with KM. It also happens randomly.
Thanks for the write up. I'll follow those steps over time.
I did reinstall catalina from recovery, and lots of other maintenance. The problem persists (and lots of others, but things seem a little better overall).
Regarding the window resizing, I've been documenting more and more quick fixes, hoping they might give some clues.
Thanks
If I cant find a fix, I'll migrate a lot of this to BTT too I guess. It's a shame though, I was hoping to retire BTT, it's been buggy for me. Specifically, when I copy and paste triggers and actions, it silently deletes some of them!
I've also had issues like you describe, where BTT interferes in window movement without me pressing the modifiers.
I have the same issue with BTT so I only use it for a few specific trackpad gesture related things I can’t mimic with KM.
@cdthomer
I posted about it recently on the BTT forum, because I think I found a fix, or at least a clue.
Apparently it's fixed? I don't know, my subscription just expired.
Hey @james8231 I'm having the exact same problem and it's driving me insane.
I have some complex window management macros that set up my desktop by moving 4+ apps sometimes and having to hit the key trigger multiple times is beyond annoying…especially because I sometimes move between these different window states.
Have you had any progress in figuring out what the root problem might be?
I still don't have a clue what the issue is. It still happens on my wife's MacBook which I use sporadically, but it's not present on my iMac which is what I use on a daily basis so I don't worry about it.
I did however make some adjustments to my critical positioning actions to ensure they are positioned appropriately. Basically I placed the manipulate a window actions inside a repeat action, and use a global variable to set that number. This way I can make all of those actions repeat as many times as necessary by just changing the contents of one variable. It's a band-aid, but it's an effective band-aid. See the screenshots for more info.
I still have the same problem. I paid for Moom, it works 100%, and have been removing all window management actions from my KM macros
Dang that's a real bummer. Unfortunately Moom doesn't work for my use case, so guess I'm stuck for now.
I've been fighting this too.
Thanks for that tip. I installed Moom and it's working great. I haven't noticed any instances of needing to hit the keystroke multiple times, and the window movements seem faster and more instantaneous. Totally worth the 10 bucks.
Are you sure Moom won't work for you? You can define window positions to be activated by a keystroke, and then you can trigger those using a Type a Keystroke action in KM. The keystroke could be some obscure complicated key combination that you would never hit manually.
Moom also has the ability to save complete window snapshots for an app. Those can be triggered by a keystroke, a menu or via AppleScript.
Unfortunately no.
My use case was that I would have a single keyboard shortcut that would place windows for 3, sometimes 4, and 5 different apps at once. And sometimes the same keyboard shortcut would change a window's position or size depending on my monitor configuration. So, Moom is just too limited for my use case.
Not a Moom user, but I know it has some AppleScript support. Might you be able to eg create a KM macro that:
It seems as though the saved snapshots executed via AppleScript would handle this part.
This might be the tricky part. If you can detect the monitor layout in AppleScript, then you could branch the AppleScript based on this. I don't use different monitor configs, so I don't know that much about it. But there's a third party app called Display Menu that has AppleScript support. It can list monitors connected and their resolutions, but that won't help if by configuration you mean monitor positioning relative to each other.
WOW! I thought i was crazy because I was having this issue a few times a week but never with any consistency so I ended up moving to Moom a few months ago but I did put together a solution when using KM to just re-run the resize action with a .5 second break between that was able to solve the inconsistently.
Also since I like KM Pallets I now just have it send the keystroke commands to via AppleScript that I have mapped in Moom
I understand why you are placing the Moom keyboard shortcuts in KBM so as to be able to use a conflict palette (an idea I will steal), but I don't understand why you are Applescripting the keystrokes to trigger Moom events instead of just using the native KBM "Type a keystroke" action, which would avoid the need to look up key codes, etc.
Well mostly because.. I didn't think of that.
I think I may have tried that originally as it is the most obvious answer and perhaps it wasn't working properly or it was delayed. Going to experiment right now.
For your inspiration here is my "Move Windows" Macro group that I trigger with CON+W for the palette
