I've had at least one grip that just wouldn't work reliably...same sort of "bend"/torque to it.
As you've noted, it'll cause all sorts of wonky issues. Reseating the grip is temporary most times...it'll move eventually.
Are you using the stock trigger stirrup? (probably not so stock any more if you've been bending it
) Are you using the stock trigger?
If you're using an aftermarket trigger, especially one with an over travel set screw, start with the set screw out (away from sear) all the way. It sometimes doesn't take much more than a 1/8th-1/4 turn to put it too far from the sear. If your grip is going all wonky...that'll screw with things too on the backlash setting.
If you're just testing, take your mag release out...then depress the trigger...if it trips the sear (cause there's nothing stopping the trigger from going back) then you know you need to adjust the space between the rear edge of the trigger where it contacts the mag release.
Or junk it, sell it for parts and start over....