I can't visualize what you are describing. Trigger snags the thumb safety? Striker block?
The "catch", for lack of a better word, on the back of the trigger safety... the part that stops the trigger from moving further to the rear, is engaging the frame on a normal trigger pull, because the resistance from the spring in the trigger safety is greater than the resistance in the trigger spring. Does that make more sense?
I have this setup in a full size 9mm. The trigger spring is a little lighter than I would like also. Mine works OK on the firing stroke but the trigger seems to lag my finger on reset. I would field strip the gun, leave the sear in the up position with the wire thingy, remove the trigger spring and check for friction in the trigger movement. It seems that either the trigger safety spring is stiffer than average or you have some excessive friction in the trigger which combined with the trigger safety spring overcomes the light trigger spring.
Or you could do the easy thing and call Apex and speak to Flork.
David E.
The trigger seems pretty free to swing on its pin with the spring disengaged. Either the safety spring is a little stiff (this is a brand new pistol, maybe it'll break in), or it's possible it's just how my finger engages the trigger. If the latter is the case, I'd rather have a slightly heavier trigger pull than change my grip up.
Once I get it tested out, if I just can't bear to have that extra pull weight, I'll talk to Apex... as it stands, this is already the lightest trigger of any striker-fired pistol I've owned, and it feels much better than stock. Definitely no complaints about the AEK as a whole.