Uh, I would offer all kinds of lame IT advice about your cookie settings but I think you already know it. I’ll recheck the board settings but I don’t think anything has changed. (Will, are you out there?)
It seems to be working now. I never had to login on either my phone or laptop and then it kept coming up unlogged in for a while on both.
But I have rebooted this laptop into multiple OSes, and just restarted Safari and was logged in.
See how it does on my new giant phone (that doesn’t make phone calls).