Nearly impossible to connect to Remote

SuperFury

Hi there, since a few weeks it is nearly impossible for me, to connect to my Windows machine - when establishiung a connection the screen appears, but shows only the first top 1/3 of the screen - reminds me of loading pictures back in the days of analouge modems - I dont know, what changed since it worked - It feels like, its getting worse, when the remote has multimedia Applications open.

What can I do to make it work again

Connection is a remote on the same internal LAN, connecting via associated tv-account.