Advice Sought. Weird FX Impact behavior

Fearn, was yours ever shooting well at 100? Mine was consistently right around MOA or slightly better at 100 yards (indoor range, so no wind) and then it just went bonkers. I've got the velocity back up, but my ES is now about 25 (up from 7 or 8). I'm thinking its an internal issue, but I'm not sure what.

Oh yes. It was 1 Moa at 100 (outdoor). I decided to tune it to shoot a bit hotter. Post that it’s shooting lights out at 50/70 but at 100 it’s 4-5 inch groups. At 158 yards it hits a 7 inch target 6 out of 10 times. But I can feel that there is something wrong. Just not sure what is going on. Have ordered a few C3 bumpers. Will open up and check if that’s the reason for the opening up of the group. My std dev is 7-8 FPS. Extreme spread is about 10-12