I have a simple macro of 3 steps. The first is to Select or Show an item from the menu. Then 2 Press Button actions. The first action happens right away but then there is a 3-4 second delay before the other 2 actions finish. The delay seems specific to that first action as it doesn't occur with other macros that don't use it.
First off, it looks like this is your first post, so welcome! This is without a doubt the best forum I have ever been on, and there are a lot of great people here who are glad to help.
Now as for your question, if you could upload the macro here it would help us see what might be going on. You can do this from within Keyboard Maestro by clicking File / Share / Keyboard Maestro Forum and selecting either the image or the file.
Or you can screenshot it if it's a small macro and upload that by dragging the image file directly into the text area.
It sounds like the app is doing quite a bit of work once the menu is selected. I would put a pause action in. Start at 4 seconds and see if that works. Then halve it and see if it still works - and repeat until satisfied or it b4comes unreliable.
The key word here is “reliably”. On my 15” 2015 MBP It can vary quite widely as to how long an action - including switching to
an app - can take.
So I’ve tended to adopt the approach I suggested. For some use cases I’m prepared to take a few seconds’ delay - as it gets the job done accurately. For others that’s no good at all as I’m looking more for speed and minimised interaction.