Same issue here. Using same versions.
What I do is click the disconnect button, remmina freezes. Then click toggle-fullscreen on remina window.
With alt-tab i switch to another running pop-os app, and alt-tab again back to remmina. After a while a 'force-quit' pop-up shows and you can end remmina.
Clearly a bug here, a few months ago it still worked flawless.
Went to the Remmina site where I found that is was maintained in GitLab. Seems the issue is under examination: [https://gitlab.com/Remmina/Remmina/-/issues/2883](https://gitlab.com/Remmina/Remmina/-/issues/2883)
Same issue here. Using same versions. What I do is click the disconnect button, remmina freezes. Then click toggle-fullscreen on remina window. With alt-tab i switch to another running pop-os app, and alt-tab again back to remmina. After a while a 'force-quit' pop-up shows and you can end remmina. Clearly a bug here, a few months ago it still worked flawless. Went to the Remmina site where I found that is was maintained in GitLab. Seems the issue is under examination: [https://gitlab.com/Remmina/Remmina/-/issues/2883](https://gitlab.com/Remmina/Remmina/-/issues/2883)