I recreated your macro and I also get the beep (on an iMac with macOS 10.15.2 and KM 9.0.4). To me it seems that nvALT somehow doesn’t get the F11 keystroke from KM.
This was my test macro: [test] NValt (Filou).kmmacros (3.6 KB)
But why aren’t you doing it just like this?:
[test] NValt (alternative version).kmmacros (2.1 KB)
No need to setup a hotkey in nvALT, since the KM action brings nvALT to the front if it’s running, and if it’s not running it will launch it and bring it to the front.
…unless I’m missing something.
By the way, if you uploaded your macro, it would be easier for others to quickly test your macro. Recreating a macro from a screenshot, even if it’s simple, always takes a minute or more. Uploading a macro takes you 10 seconds 