Could be a spring that wasn't fully seated. Maybe the trigger bar and dosconnector weren' quite lined up properly. Hard to say for sure. Glad it's fixed for you now.
Glock 19 G4 Gray | Glock 17 G4 FDE | S&W M&P 22 | S&W M&P 45 | S&W M&P 9 | S&W M&P Shield 9 | Ruger GP100 4"
Sig P226 MK25 | Sig P229 Extreme | Sig P320 F | Sig P320 C | HK USP 9 | HK USP 45 | HK USP 45 (Tan) | HK VP9
Daniel Defense DDM4 V4 | Arsenal SGL 21 | ASA SBR | Savage Mark II FV-SR
Mossberg 590A1 20" SP | Mossberg 500 Cruiser