That's generally true of most things in Wayland. It's poorly designed and then badly implemented, by multiple different compositors in different ways, leading to endless bug reports and broken software.
What's so frustrating is that this is my Linux desktop experience since I have been using it. Clipboards not surviving shutdown where at one point not working, then a bunch of people got together to fix it up and now it's broken again. My Wayland experience is a massive flashback to 2004.
Yes, I know. I remember several years ago being super excited about Wayland. But every time I have tried it, it just falls over in so many different ways. I have given up.
About copy/paste in particular, I have solved it for myself because I work almost exclusively in the terminal and the browser, both of which stay running all the time and therefore acts as a clipboard manager for any copy/paste that happens in it. I am just waiting for my terminal of choice to get support for copy/pasting arbitrary mime types, which its maintainer has said he is going to implement.
