Hi, I would reset the preferences: reset Photoshop's preferences by holding down Ctrl+Alt+Shift (Pc) Cmd+Opt+Shift (Mac) as you click on Photoshop's icon to start it up.
See: https://helpx.adobe.com/photoshop/using/preferences.html
If you do have access to the menu Edit>Preferences (Pc) or Photoshop>Preferences (Mac), it is possible to reset them from the General submenu.
Were you using multiple screens then remove one?
Which version are you using, 23.0.1, (check in help>system info...)
Please post a screenshot when such problem occurs.