cut and copy (ctrl-x and ctrl-c) sometimes just...don't work (don't put the text in the buffer)

I've been noticing this throughout much of the Fedora 31 cycle, but for a while thought I was maybe just crazy. But no, it's definitely happening, and Kevin Fenzi says he's seen the same.

It's a pretty simple problem: sometimes I select some text (either with mouse or something like "shift-home", I don't think it matters which) and hit ctrl-c or ctrl-x. Then I go somewhere else and hit ctrl-v, and...it doesn't get pasted. In the case of ctrl-x, though, the selected text is erased (so I have now basically lost it).

I've definitely observed this happening with Firefox (Wayland backend) and hexchat (which I think is on Xwayland). For instance, I just saw it happen entirely within hexchat without any context switching at all. I started typing a line, but then wanted to type a response to something that was said while I was typing. So I hit shift-home (to select the text I'd typed) and ctrl-x to cut it (the text was correctly erased at this point). Then I typed the new line and sent it, then hit ctrl-v so I could finish off the line I was previously working on...but it did not show up. The text I'd written was basically "lost".

I'm assuming this is to do with the newish clipboard manager, so filing against Mutter. Right now I'm on mutter-3.34.1-4.fc31.x86_64 , but as I said I've been noticing this for some time now, I couldn't say precisely when it started though.