For about a week now, I've been unable to connect to dominion.games on my windows 10 laptop. I get the "server connection was closed or could not be established" message. I've tried multiple browsers (chrome, edge), and have tried clearing cached data. I can connect and play just fine on my cell phone. I've attached a screenshot with devtools open, so maybe you more tech-savvy folks could help me out.
The error is an invalid certificate. I remember that around christmas there were certificate problems, which were resolved (not immediately but not longer than 1 day or so). That would roughly coincide with your timeline of when the problems started.
That problem should clear itself after some time, but 1 week is certainly way to long. I'll ask the dev what can be done from your side.