Could you please confirm the version of macOS, the Mac M1 Pro?
If going back to LrC 11.2 helped, then it could be possible that the v11.3 install was incomplete or corrupt. Please try reinstalling 11.3 and follow the steps mentioned below.
You can start by ensuring Lightroom has the permissions needed on the Mac by following the steps suggested below:
Go to the System Preferences for your Mac, then Security and Privacy, then select the Privacy tab.
Then select Accessibility from the list to the left & check if Lightroom is added to the list with a checkmark in front of it.
If Lightroom is not a part of the list, please add it by unlocking the window first using the lock at the bottom left, then clicking the + icon & navigating to the Applications folder.
Also, grant permissions to Lightroom under Full disk access found in the same list as Accessibility.
Once done, lock the padlock to save the change.
This will ensure Lightroom Classic can read-write uninterrupted and then go to Lightroom > Preferences > Performance > Use Graphics Processor > Set it to Off if it is on Custom or Auto. If this shows any differences, please check this article to troubleshoot further: https://helpx.adobe.com/lightroom-classic/kb/troubleshoot-gpu.html.