Well my 2.0 compact 9 was shooting 4” low at 15 yards also. Sent it in and had new sights installed. Got it back two to three weeks ago but have not had time to take it to the range yet.

Will try the end of this week and report back. Rastoff knows of my troubles.
Plant has it set to poa/poi at 25 yards as requested. I’ll let you know my results by the weekend.