I had the same issue last week, during playing a game, I wanted to click on the 'pass' icon to pass my turn. My two opponents both gave me the 'look at the time' reaction, and nothing I could do, the game was unplayable, had to quit.
@James-Hook Thats just us, your fellow players answering here in this forum to the best of our knowledge. By the way, steam has a browser cache, too. You can also empty the bowser cache you use when you are not playing on steam.
But most likely, the problem is not on your end, but caused by the less than ideal server stability of Catan Universe. This long existing nuisance has increased during worldwide Corona Shutdown. I suggest to try and login not during primetime, but in the wee hours of the morning, or late at night, when servers will be less crowded.