Focus issue when playing with 2 Players

Hey there…
This issue is driving me crazy - I personally think it’s irreleavant but my “master” want’s it to be solved.

So the situation is as followed:

I start the game with 2 players in PIE and dedicated server. On both players a UI shows up to select a team. Now, I tab over to the viewport that is not currently on top before doing anything on the one that shows on top. I select my team, tab back to the other client and select my team there too. This programatically makes the UI to close, and also calls Set Input Mode Game Only on all PC’s. However, even though I just clicked the UI in my active viewport client, mouse and keyboard input now is still on the other one. So I move the other player - until I press Shift + F1 and reacquire focus.

I tried other nodes Like Set Input Game and UI and all that stuff - nothing gives desired results. Anyone any idea how to fix that or just a simple “that’s a bug, can’t do anything about that” would be enough too…

All the best,