[Hectic]

I'm mot 100% on tue design of the trigger but what you describe sounds like a cutoff lever or trigger shuttle issue. When the gears rotate a cam activates the cutoff and lift the trigger shuttle to pop off of the trigger and return to battery.
(This is in a normal aeg I mean)
So if the shuttle is worn it could be popping off early. If the cutoff is damaged or bent it could engage a little early.
The trigger itself could be worn and the contact slips easily off.
If you pull the box and rotate the gears by hand you should be able to see how/when the cutoff occurs to get a better idea of what may be the culprit.