Impossible to set Keyboard Shortcuts

Since one or two versions of C1, setting new keyboard shortcuts has become impossible : every time I enter a new keyboard value in the appropriate field, it immediately changes it to some random other shortcut. I am trying to set a shortcut for the Yellow color tag, using Shift+*, it shows then Shift+$for a second, but then removes it and either sets it to Cmd+4 or Shift+4... Same happens if I simply use the * key above numerical keys. Now, if I can understand that this might mean this shortcut is already taken, searching for it using the "search" bar gives no results, so it seems it ISN'T already taken.

What the heck is going on ??? This has been happening for a while now and it's just really annoying.