timney trigger not resetting

i have a 3lb timney trigger that came stock in my 16 inch pof m4 . i have probably 300rds through it and all of a sudden the trigger wont reset 50% of the time . i’ve been shooting good ammo ( wwb, blackhills , lakecity ) i have a stardard buffer , that i put back in replacing the h buffer that was in there when the issue started . when i manually cycle the weapon it doesnt happen , only during firing . when it fails to reset , if i safe the weapon then go back to fire i can feel the reset and the weapon will fire . upon inspection the pins are snug and in place , the selector switch looks okay , nothing looks broken , . anyone have any ideas ???

The screw ahead of the disconnector, turn it in 1/4 turn at a time until it stops doing that. If you still have your instructions it’s in there (best bet since I’m kinda going by memory here).

thank you - i’ll give it a try

yeah it worked - thanks !! there were no instructions supplied with the rifle . they would have been helpful