Hey everyone. I need help with the following problem.

I have two laptops with Ubuntu 20.04 and I have been using Remmina to connect to a Windows 10 PC for many months. This worked fine from both PCs, but a week ago it stopped working from the one laptop (Dell) when I changed the resolution setting from "Use client resolution" to "Use initial windows size". I changed it back but I still could not get it to work. I tried various combinations of resolutions and colour depth settings without any luck. Then I tried checking the Advanced Tab setting "Ignore certificate" and it worked the first time but the second time (and later tries) it stopped working again. Unchecking the "Ignore certificate" setting had no effect.

I tried with the second laptop (Lenovo) and everything was working fine, but when I changed the resolution setting it stopped working as well. I tried with various settings combinations but I could not get it to work again..

For a few days now, in both laptops, when I try to start the connection I get a black screen and a couple of seconds later the Reconnect message (0->1 out of 20) which repeats itself (it never goes to 2, 3 etc. out of 20). I have deleted the "known_hosts2" file in the .config/freerdp/ directory but the only effect was that I get an initial message to accept the certificate when the connection starts. I select accept and the result is the same black screen and then the Reconnect message. I have also tried with changing the "Security" setting from "Negotiate" to "TLS" but without any effect.

Another thing I tried was to remove the stored password of the Windows 10 PC from the Remmina settings. The effect was an initial challenge for the password, but when I type it, I get the black screen and Reconnect message again.

Can anyone help me with this? I can still connect to the Windows 10 PC from a Windows laptop using the Windows Remote Desktop client, but it is more convenient for me to work with Ubuntu.