FWIW. Shooting Glock about 2 years. Had the down and left problem till last week. Right hand dominant, tried all kinds of different holds and trigger technique with no help.
Watched a UTube video last week where the shooter stressed what you do with your non dominant hand. Tried placing my left differently and the bullets started flying straight instead of making left dives.
Maybe this will help, maybe it will just rule out one possible problem. Good Luck. It feels Soooo good when the bullets start going strait!
"A little learning is a dang'rous thing; Drink deep, or taste not the Pierian spring: There shallow draughts intoxicate the brain, And drinking largely sobers us again."