Libreoffice calc suddenly stops to copy and paste formulae

I was used to copy and paste (with ctl-C ctl-V) a formula with automatic relative update of the references (even from one cell to multiple cells).

This suddenly stopped working today (both on a new spreadsheet and existing ones). ctl-V copied the formula result (unformatted text) and in a single cell.
After a web search (which seems more to find the opposite case) and some attempt to solve it resetting the user profile, I found an obvious solution, which I wish to document here if the same happens to anybody else.
Apparently this is due to an interaction between LibreOffice and the Linux xclipboard utility. If xclipboard is open it intercepts the ctl-C and causes the misbehaviour. Closing xclipboard is enough to restore the normal behaviour !

I have not yet understood whether your description is correct. However, I would like to ask you to write the part “The Workaround” here in an answer box. Thank you very much.

Is it “suggest a solution” ?

Yes.

Not sure what you mean by “answer box”. Is it “suggest a solution” ? YES
Anyhow the workaround is this:
If the problem occurs make sure you do not have an X11 clipboard open (like xclipboard). Close it and the normal behaviour is restored.

EDIT: @Hrbrgr replace this complete text with your answer.