Hello! I wonder what this mod are doing for the tone?

Hello tubelovers! I own a Ceriatone Overtone HRM 50 W, and I'm wonder if anyone else have notice, that the overdrive channel has a tiny bit lower volume than the clean channel? It's without the PAB. I have to turn up the overdrive volume a bit to balance. With the PAB it's equal. Maybe it should be that way and I'm just stupid! I have sometimes also had a problem with a volume drop on the overdrive channel! This was with the PAB on! I have tried to see if there was any cold solder. impossible to see. but I resolder some that look suspicious. Anyone else that had this problem?
Have a nice day!