Firstly, I would like to thank all involved in development of 20.04.
I've noticed an issue when "Show Desktop Icons" is disabled through Mate Tweak, the global application menu becomes a little buggy.
Specifically, if an active window is minimised, its title remains in the global menu, instead of changing the the expected "Desktop" item.
Furthermore, if one hovers over the menu items in steam e.g. "Store" or "Library", then the global application menu shows "Desktop".
I hope this helps and is not a duplicate post.
Kind Regards
Darryn Jordan