If anyone does figure out what setting breaks things, that would be great. At the moment I don't really know due to not owning Apple stuff, but a lot of people do use Apple stuff so it would be great if I could advise on the solution when people ask.
I know that Safari's privacy mode is too aggressive, but that's about all I know for sure.
It is definitely private mode on Safari on my iPhone and on my mac. Switch it on and I am logged out, switch it off and I am logged in. I put firefox on the phone and it works fine no matter what settings I use.
If anyone does figure out what setting breaks things, that would be great. At the moment I don't really know due to not owning Apple stuff, but a lot of people do use Apple stuff so it would be great if I could advise on the solution when people ask.
I know that Safari's privacy mode is too aggressive, but that's about all I know for sure.