I recently ran through the same list with similar results. Basically just gave up.
openSUSE
openSUSE is an open, free and secure operating system for PC, laptops, servers and ARM devices. Managing your emails, browsing the web, watching online streams, playing games, serving websites or doing office work never felt this empowering. And best part? It's not only backed by one of the leaders in open source industry, but also driven by lively community.
Small issues like this make me miss Windows a bit. ShareX in this case.
Linux definitely needs more tinkering. Which is bad, as this example shows.
I still stick with it, in the hope that more development power will flow into it as time goes on.
Are you using Wayland or X11? It may be worth switching if you're having problems, as that many programs having issues suggest the problem is Gnome and the WM. Most likely Gnome with Wayland would be the problem?
Other thing to consider is video drivers but is unlikely of the desktop is drawing fine.
I use Tumbleweed and use Spectacle.on KDE on both Wayland and X11 without issue.
Ah yes, forgot to mention. Using Wayland (X11 doesn't even install by default anymore). Added that.
Video drivers are fine. At least I have no issues with any display otherwise.
That may be something worth trying. Install X11 and dodge Wayland for the time being. It is definitely more limiting than X11 in my case. At least until the devs of various apps catch up.
Ksnip on Linux Mint Cinnamon X11 works great.
Maybe. But I have a different system. Am not changing distro and DE just to get a screenshot tool working.
Thank you for your reply. I do need to get a tool working with my configuration, though.