Been experiencing this issue for a while, a year or more most likely, currently running the latest beta 12.0.2 Beta12
I have a number of programs that I launch via a .BAT file and noticed this occurs regularly with these, but I also have had it when launching a pinned item from a desktop shortcut/start menu etc.

Screenshots attached:

Screenshot 1)
Firefox was opened by clicking the circled pinned icon, at some point the Firefox tab was moved to another monitor (as a 2nd Firefox instance with the original circled Firefox tab still running) and then moved back to the original monitor.
It didn’t combine with the original tab (which had been shut down since) but the right-click menu shows it as Unknown not Firefox

Screenshot 2)
BAT file launch example: You can see StreamLabs hasn’t opened on its pinned taskbar item, but it also doesn’t show the correct exe name in the right-click menu, shows Windows Command Processor" instead.
All the other pinned taskbar items in that screenshot were launched from the same BAT file, but this issue can occur with any of them, or multiple at the same time.