"pin it by right-clicking on the running AnyDesk instance" - I meant right click on it (the red icon) on the taskbar and pin it.

Sorry, it becomes difficult and I don't have more time for it. That's not what I meant. Try reading my previous message again. If you don't know what "pin" and "unpin" mean on the taskbar, read about it online.

Yes, that explains it. The ids "Microsoft.AutoG..." and "prokzult ad" are different, that's why they're separated.

First thing I'd try to do is unpin the pinned items and then pin it by right-clicking on the running AnyDesk instance. Perhaps the pinned item will get the "prokzult ad" id and both will group.

I'm looking for the second instance of this, on the taskbar and in the list.

That's unexpected, the Windows default behavior is to replace the pinned item with the running task when it's launched. So there's something weird going on here. Maybe if you attach a screenshot with Taskbar Inspector and the full information it will provide a hint.

No, I don't see the second AnyDesk item. Not on the taskbar, not in Taskbar Inspector.

Yes, it looks like it should work, not sure why it doesn't. How does it behave when the tweaker isn't running?

Also, next time post the full screenshot so that both items can be seen, perhaps there's an explanation in the full data.

Firefox is not related to what I wrote, changing the configuration for AnyDesk's id in Taskbar Inspector affects only AnyDesk. You can change any other global settings and any other per-id settings however you find comfortable.

I see that you have grouping enabled, but "don't group pinned items" enabled as well. So you don't need to enable grouping for AnyDesk (as that's your global configuration), but you should enable "Group pinned item" instead.

The id is the string that starts with "Microsoft.AutoG...".
For your case, the easiest thing would be to enable grouping for the id, if the two AnyDesk windows are the only ones or if you want to always have them all grouped. Just right click on the id and enable grouping.