As a former MVP, I've tried a few things to remedy this since it emerged a few days ago. I'm using Microsoft 365 for Excel and other Office apps, but this only occurs with Excel. I can reproduce the problem when I copy a formula and try to paste the result as a value. Another feature of the problem is that I also lose the ability to highlight a cell. I can usually access the cell with my mouse but I don't see it highlighted until after the copy function starts working normally again (usually by closing and reopening the file).
The only recent system changes were 2 weeks ago installing the 2022-07 Cumulative Update for Windows 11 for x64-based Systems (KB5015814) & a few days ago installing an Intel graphic driver. I have also installed another 2022-07 Cumulative Update for Windows 11 for x64-based Systems (KB5015882). The cumulative update predated the problem by a week so that is unlikely to be the cause. I uninstalled the graphics driver and rebooted but it made no difference, so I've eliminated that as a cause.
There is therefore no system change that I can tell which is responsible for the problem.
I've done a quick repair of 365 but it has made no difference. I wondered if it was because I've saved (through autosave) multiple copies of the main file I use daily but it also happens in other files where this is not the case.
I might try a safe reboot to see it that makes any difference but otherwise, I'm stumped!