xrdp frame rate low

Hello,

I have set up a Virtual Machine via ESXi:

Ubuntu 18.04
CPU: 8 x 3.5Ghz
RAM: 64GB
SSD: 200gb
connection speed: ~800Mbit/s

I have only installed xrdp yet.

Connecting to it via my win10 surface book gives me a very low refresh rate. Opening firefox takes like 3 different renderings and 15 seconds. (My connection speed at home is ~200Mbit/s.)

Do you guys have an idea why it´s so incredibly slow && how to improve perfomance?

Thanks in advance