Third time reporting this bug, have reported it in both Dominion Discord servers.
Notifications are not happening all the time if you are tabbed out. Often, when my opponent finishes their turn, I get no notification it is my turn, when I am looking at another tab. When I come back to the tab, my opponents turn has not played out at all for me, the page was frozen while I was looking at another tab. My opponents turn then starts to play out while I am looking and will freeze again if I look at another tab. Meanwhile my opponents turn has been over for a while and they are annoyed I'm not doing anything, and I can take no actions as I wait for their turn to play out on my screen. Sometimes I come back and their turn plays out, THEN it tells me I resigned. None of this was an issue until the new interface.