One of your valves may have a cross-over leak which lets the hot-cold interchange. This will make the hot line warm as well as the cold one, and limit how hot things can get elsewhere in the house. As to the hot volume, that hose may have a kink in it or that valve may have a screen filter on it's inlet that is plugged.
All modern anti-scald valves have a max temp adjustment to them...yours may be set incorrectly. This adjustment might be a screw, a cam, a piece of plastic with notches pushed into the handle, etc. Its whole purpose is to limit hot hot the valve can get - you may need to adjust that.