Strange conflict between Firefox, clipboard and Konsole

I have a Youtube-dl script that takes a URL from the clipboard and downloads it.
I use the terminal (Konsole) to run the script
Copying the URL from Chrome works fine.
When trying the same operation from Firefox, the wrong clipboard content is pasted into the script, even if I clear clipboard history.
If I manually run the command, e.g. youtube-dl -o “%(title)s-%(id)s.%(ext)s” -x --audio-format mp3 “”, it works.
My system is Manjaro 5.9.16 KDE Plasma 5.21.4
I tried resetting my firefox profile - same results.

Any ideas?

You running in a Wayland session by any chance?

I do, and I see the exact same thing. Sometimes copy pasting from firefox to Konsole fails. :stuck_out_tongue: