This may sound like a repeat, however have you tried removing Lightroom Classic completely from your computer, that means cache, preferences, settings (which I would back up somewhere else before deleting)? You need to have a back up copy of your Lightroom Catalog somewhere else on another drive perhapds. THen restarting the computer and then installing LRC ? If PS is working, it is possible there is a setting, cache, or pref that is blocking your smooth use of Lightroom Clasic.
... View more