Muted trumpet/con sordino is buggy

Seems like con sordino is missing completely from notes with accents, and is extremely quiet at dynamics below mf. Although at least audible, dynamics mf and above still sound very weak and quiet as compared to their non-muted counterparts. (as a trumpet player, mute is used more as a timbre change than dynamic change. It could easily be more shrill and louder than a non-muted trumpet in the right range/dynamic)

I've only tested this with trumpet, so I don't know if it works with strings as well.