A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
The Copy & Paste and Drag to Autofill problems in Excel are currently widely reported in Excel as being caused by the latest Office update (KB5002914).
Try uninstalling that update and restart your PC, if that does not resolve the problem, Microsoft indicate they are working to resolve this bug and will release an update as soon as possible to resolve the problems.