Interesting that this thread popped up because I just begin experiencing this yesterday. If several of us are experiencing it at the same time it makes me wonder if its something on the server side (i.e. Hyatt end) rather than the endpoints. I was able to use Microsoft Edge as a backup. But this this morning still a no go on Chrome and Firefox. Also, if cookie related, it's a little surprising that it would happen to both browsers (i.e. Chrome and FF) almost simultaneously (it started happening at the exact same time yesterday afternoon)

Regards