The issue is not completely described. What actually happens is that the icon is of size 512x512 and it’s placed in the wrong location. I have an aliased command to fix that on every update, but I’d like it to be fixed naturally too.
I was able to get the program icon in the KDE task manager using GitHub - probonopd/go-appimage: Go implementation of AppImage tools. Still experimental (I think) and pinning it to the task manager from the application launcher menu shortcut, but found another issue. It seems that each launch of Anytype creates a differently named .mount_Anytypxxxx folder in the /tmp/ directory, and so clicking the icon in the task manager creates a 2nd one for the currently opened session because it’s pointing to that new folder. This is on the latest OpenSUSE Tumbleweed. @Srinath