taskbar icon cannot hidden though app configured to do so

all i can provide is nothing more than the trivial description:

running 7+ taskbar tweaker v5.2.1

0. tray icon is visible

1. click on tray icon > app window appears

2. click on "settings" > "settings" dialog box appears > option "hide tray icon" is not checked > check it > click on "done"

3. tray icon is still visible

4. again, click on "settings" > "settings" dialog box appears > option "hide tray icon" is now checked

5. tray icon is still visible

6. exit and re-start app / restart windows etc.

7. tray icon is still visible

I hoped for some information such as the Windows version or maybe conflicting software. The tray icon hiding functionality haven't changed for years in the tweaker, and I haven't had problems with it. Basically, it uses the documented NIS_HIDDEN flag to hide the icon, so I don't see a reason for it to misfunction.

interestingly, the issue (along with the tray icon, too) has meanwhile disappeared

though app version has remained the same i.e. no update seems to have occurred

Maybe it was a temporary Windows issue. I'll close the bug for now, let me know if it comes back.