I am running Firefox with the Windows 10 operating system. I have been using Google Docs in Firefox for several months without issue until a couple weeks ago. Around March 7, the copy and paste shortcuts in Google Docs stopped working in Firefox. I had made no changes to Firefox, any of the extensions, nor any settings between the time the shortcuts were working and the time they were not. In an attempt to locate and correct the problem, numerous tests were conducted: refreshing and reloading Google Docs; testing the shortcuts in other websites, Word, and Excel; uninstalling and reinstalling Firefox; setting security settings to "Standard"; disabling all extensions; disabling all extensions and deleting all website, cookie, and history data; and testing the copy and paste shortcuts in Google Docs in Microsoft Edge. The copy and paste shortcuts functioned normally in other websites, Word, Excel, and in Google Docs loaded in Microsoft Edge. All other tests showed no change in the functionality of those shortcuts. This demonstrated that there is a problem with the compatibility of either Firefox or the downloaded version of Firefox with Google Docs.

Are there any suggestions on how to fix this issue?