Comment 2 for bug 2031538

Could this page https://community.spiceworks.com/how_to/195154-how-to-set-up-and-use-remote-desktop-connection-in-ubuntu-linux give a solution (shown below) to this bug even though it applies to Ubuntu 18.04 and the bug gives a slightly different problem?
Solution is:
he problem is related to the xorgxrdp package and the particular changes in Ubuntu 18.04 that caused xrdp capability breakage. In this guide, we use Ubuntu 18.04.2 to configure xrdp. To solve the empty blue screen problem, install the relevant xorgxrdp-hwe by executing the following command:

sudo apt-get install xorgxrdp-hwe-18.04

To check the current version of Ubuntu, use this command:

lsb_release -a

Restart the xrdp service (daemon):

sudo /etc/init.d/xrdp restart

After the required package is installed, open the RDP client. Then, try using RDP to connect to your Ubuntu again.