The upper guide bar sounds like the problem on the saws, they have to be able to move all the way up and down to within 2" of the stationary platter to cover the exposed blade when not in use. They're also supposed to be lowered within 2" of product being cut, as cited above. Not everyone likes to do this ( line of sight / vision ) but that's the rule.
Upper guide bars tend to sieze up when they aren't moved often. The best way to prevent this is to move it up and down and oil it daily. This will prevent it from rusting in place, it will also break up any sanitizer residue that builds up inside slide hole ( looks like light blue crystalized powder ) Simple to fix not worth the fine.