I apologize for bumping this thread again, but I'm really out of my depths on this one and it's not a minor issue either (Libreoffice Writer is an important application for anyone who's working for many hours on documents each day).
I did see an update for mutter (3.34.3+14+g59e9b073a-1), I was hopeful that this would have been a patch solving the issue, but unfortunately nothing has changed.
I have been prompted to install a newer kernel, too. Currently using 4.19.99-1 (LTS and recommended). Is there a possibility that a newer kernel would make a difference?
If there is a way around this problem, or a patch, I do not know how to proceed in making those kinds of modifications to my system. If there is any relevant documentation that I could read, I would appreciate it if someone could show me to a link.
Lastly, it may be useful to note that this issue did not exist when I first installed Manjaro 6 months ago.
Thank you and I wish to hear from someone more knowledgeable about this soon.
Edit: I tried using copyQ as d7rk mentioned to see if it is any better, but it makes the task way more time-consuming.
The copy-paste problem inside a LibreOffice Writer instance persists and essentially what I experience (even with copyQ uninstalled) is that the only way I can successfully paste a text is if I double-copy, meaning that I copy once and then one more time. Only then it appears to be "remembered" by clipboard.