Try setting Preferences > Performance > Use Graphics Processor to Off. Then update your graphics driver by going directly to the manufacturer's web site (solution 4 in this article): https://helpx.adobe.com/lightroom-classic/kb/troubleshoot-gpu.html [Use the blue reply button under the first post to ensure replies sort properly.]
Please post your System Information as Lightroom Classic (LrC) reports it. In LrC click on Help, then System Info, then Copy. Paste that information into a reply. Please present all information from first line down to and including Plug-in Info. Info after Plug-in info can be cut as that is just so much dead space to us non-Techs.