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First you should try is to switch off the GPU support from the Lightroom preferences and check if that helps to fix the issue.

Go to Lightroom > Preferences > Performance tab > Uncheck "Use Graphics Processor" > Restart Lightroom.

https://helpx.adobe.com/lightroom-classic/kb/troubleshoot-gpu.html

If this helps please check your graphic device driver if there's an update available. If it's so download and install the update an check again.

If it doesn't help please check if your monitor profile is corrupt. More info see here:

How do I change my monitor profile to check whether it’s corrupted? | The Lightroom Queen 

If this also doesn't help please provide a copy of your 'System Info'. This can be get from the LrC Help > System Info menu item. There's a copy button in the System Info dialog. Press this button and paste the info into your next forum post.