Ah, ok, found the reason in the help file under "Threads"
By default, a given hotkey or hotstring subroutine cannot be run a second time if it is already running. Use #MaxThreadsPerHotkey to change this behavior.
Obviously variants are considert different hotkeys in this context, which is why your script, GEV, works.
And with your's Rohwedder, the underlying thread it paused and the hotkey itself can finish nicely.
Which, now that I see clearer, makes much more sense in my application. Even more, I can now see that I will probably not need Pause at all.
Thx to both of you for your help!
EDIT: Since I can only mark one post as solution, I will mark my own. However, both of your's contain a solution.