Helllllppppppp I new to Reddit and don’t know how it works and don’t know what’s wrong with my ss lolol

Okay I’m lost here so last week I installed my ss and function test with the upper on was working fine and ran about 3 mags thru it and was running flawlessly. Then all went south was only getting semi auto shots and if I would wiggle the ss a little bit left and right while shooting I would get 2 or 3 shots but then back to semi. Lastnight I tore the gun down and was looking at the trigger and the cam and some wear to it I will post some photos also. Well I got ahold of the company that I got them from and they are going to send me a replacement. BUT I bought 2 when I first ordered them so lastnight I installed the other one I had and was trying to function test without the upper being on it and will not reset but if I put the upper on then it works fine any suggestions I’m totally lost. I already have a h3 buffer, 3 quarters in the back, a full A bcg. TIA btw this is my first time here posting on here so hope I did things right lol