AWS + Remmina on Ubuntu - Remmina goes into a loop trying to reconnect

I followed this article to install xrdp on AWS Ubuntu 18 ec2 instance, and everything seemed to work properly for a few days.

However, now, when I try to connect to the EC2 instance using Remmina (from another Ubuntu computer) - Remmina goes into a loop, where it says "Reconnection in Progress. Attempt 0 (or 1) out of 20." ... then it goes back to 0, without getting past 2.

Any idea on how to get Remmina to work again?

Troubleshooting steps I tried:

1) Rebooting EC2

2) Rebooting laptop

3) SSHing into EC2 machine (this works just fine)

4) Restarting xrdp on target EC2 instance/reconnecting . This did not help.