F# consistently flat

Hoping to get some ideas about what might cause F# (2nd and 3rd valves down) to be consistently extremely flat when my open B flat is in tune.

2nd and 3rd tuning slides are all the way in and despite this, I can't even lip up my F# into tune it's so flat. It's a 3 valve baritone, so no alternate fingerings I can swing.

I took it in for dent repair at a reputable shop somewhat recently, but it seems that possibly made it worse? Any ideas I could look at myself or get a pro to handle would be appreciated!