I can’t remember having encountered that behaviour, but I wonder if switching screen modes (hitting the key F three times) might help.
And you may want to consider providing some information about your set up …
Are Photoshop and OS fully updated and have you performed the usual trouble-shooting routines (trashing prefs by keeping command-alt-shift/ctrl-alt-shift pressed while starting Photoshop, 3rd party plug-ins deactivation, system maintenance, cleaning caches, font validation, etc.)?
Does turning off OpenGL in the Performance Preferences and restarting Photoshop have any bearing on the issue?