The squatter's shoulder might have some ideas to address that, which might also carryover to the bench issue.
At your height, and with likely longer-than-average arms, this seems like it could be a relatively-close grip depending on exactly how "slight" the "slightly wider" really is. Consider nudging your grip width a bit further out, but not to the point where it's a legit wide-grip bench.
Again, a video would definitely help. That'd also show what Boffin. If you're losing tightness at the bottom, that's where a ton of stress would be getting thrown right on the shoulder joint.