Just getting started with KM, so forgive me if I've missed something! MacOS 14 Mojave.
One macro I have written uses alt-ctrl-shift-N as the trigger, and it works ok most of the time. It opens my Accounts app, clicks on a Natwest Bank button to go to that part of the database, & types Cmd-N to create a new entry in that bank account. I'm delighted with the macro, and it's very quick and useful.
But sometimes (tried it just now and this did NOT happen), after the Accounts app has opened but before it clicks the Natwest button, it or something opens a new instance of my default browser Google Chrome, and stops there - the 2nd part of the KM app does not happen. There is certainly nothing in my KM macro to do this!
This happens whether I'm using Chrome at the time (as I am now) or in the KM Editor, or e.g. in LibreOffice which I use regularly.
If I'm in Finder on my desktop (no Finder window open), then the error occurred just now, but when I repeated this, it did not occur, and Chrome did not launch!
I've also turned off the KM engine & tried the hotkeys from Desktop/Finder, and nothing happened (not surprising).
Finally, I've stepped through the macro using the debugger, and it worked ok with no Chrome starting.
Unfortunately, I've not been able to establish exactly when the error occurs.
The rest of this post is on a slightly different but related topic.
I had a look at the keyboard shortcuts already on my Mac in System Preferences / Keyboard, and as an experiment created a KM macro using Cmd-Alt-D as the trigger. That combination is one of the Mac keyboard shortcuts and shows or hides the Dock (I didn't know that until today). My new KM macro opens the Notes app. and types some text in it. I've found that when I type the trigger, the KM macro runs fully, AND the Dock is displayed or hidden, so the hotkeys are having a double effect. Is this something that can be avoided? It is potentially rather dangerous! Finding a key combination that does not already have an effect is rather difficult.