Copy File won't work in Studio Code Server in HA in Firefox browser

Hi. Has anyone else had this issue? And Solved it how? (??Use a different browser??)

Within Studio Code Server (SCS) in HA in a Firefox (and in MS Edge) browser window on Windows 10, I’m unable to Copy a file from one HA /config sub-directory to another, using the LH menu of SCS or Ctrl+C.
SCS gives the popup error “Unable to read from the browser’s clipboard. Please make sure you have granted access for this website to read from the clipboard.” A “Learn More” button links to " [How do I allow VS Code to access my clipboard for reading?] (Developing with GitHub Codespaces)".
However, I cannot find any similar Settings to change in Firefox.
SCS does, on opening, warn “code server is being accessed in an insecure context. …” which might be relevant. (I don’t have a web URL & security certificate, running mostly on my local network.). In SCS I can see, edit and save my files fine.

I’m sure I used (~ 1 to 2 years back) to be able to copy a file ok in SCS… I suspect Firefox’s security has changed somewhere.

Hello Ian Jones

Try using the insert and delete keys instead of copy - paste.

Hi. Have you actually tried that out? Exactly how? and does it work to Copy the file to another directory?
Normal behaviour would be to delete the file (with a confirmation warning first). I’ve used that several times - and that’s what it did. I’m not aware of a way to use Insert and Delete for Copy. It’s not like Excel or Word, where you can Shift+Delete (ie. Copy & Delete), then Paste elsewhere. Besides, I need to Copy, not Delete or move the file.