A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
The Paste problem is now widely reported in Excel as being caused by the latest Office update (KB5002914), though so far Microsoft do not seem to be aware of the problem, the best option is to open Excel, click Help - Feedback - Report a Concern and report this to the Office Developers.
Try uninstalling that update and restart your PC, if that does not resolve the problem some people are reporting they needed to reinstall Office to restore the copy/paste functionality in Excel.