TeamViewer 14.6.2452 ghosting on Ubuntu 18.04 remote

Hi, I installed TV as a host on Ubuntu 18.04 and trying to access it remotely form MacOSX (high sierra). When I access it with both computers in the same wifi network it somewhat works but lags. When I try to access the host computer from a different wifi network the desktop windows get stuck, leave their traces (ghosting) and generally do not respond normally - this happens from a specific wifi network at my home. I have checked whether it is a speed problem by connecting via network-cable instead of wifi (at my home) - but still when I logged to the remote Ubuntu computer I could not work. I am adding a picture that illustrates the situation. What can I do? I have tried to mess with every option I could think of in TV and still it did not help.

link to picture:

https://imagizer.imageshack.com/img921/3841/ruiRPF.png