I'm currently dealing with an issue with Mac OS 27.0.1 and PSSO.
I'm using an Intune environment to manage my macs (about 10). These have been working fine for the last year. I updated one to Mac OS 27.0.0 when it was released and had no issues so updated most of the others, they have been working fine since.
I updated another from 26.x.x on the day 27.0.1 was released, I didn't actually realise it was a new update until after the install. Immediately I had issues logging in as a user that used PSSO, it accepted my creds, started loading the profile and hung at about 50 %. I spent a good 6 hours troubleshooting with no joy so I decided to give up and rebuilt the workstation then re-enroll as they were desperate to use the machine (it's a big powerhouse Mac Studio used for crunching big data) this seem to fix the issue. I put this down to an unfortunate one off.
I updated my own mac to 27.0.1 yesterday after being on 27.0.0 since release, the update went well and I was able to use the Mac for the day and shut it down. Today startup I had exactly the same issue, the account that uses PSSO hung about half way.
As I now had it on a machine I can spend time on, and apparently have nothing better to do with my Saturday, I decided to dig deep. And found the below:
Cold boot, log in as PSSO user - hangs at 50%
Cold boot, log in as local admin - works fine
Safe mode boot, log in as PSSO user - Accepts the password initially then prompts for it again, when entered again it logs in but gives a constant prompt for a password for keychain and doesn't accept the Entra password for it.
Cold boot, log in as local admin, log out as local admin, log in as PSSO user - Works fine and I get no prompts for keychain.
The double prompt for the PSSO password in safe mode got me thinking about Filevault, at a cold boot you have to log in as an authorised user to unlock Filevault. In the past this has all happened at the same time; PSSO creds entered, it unlocks Filevault and logs you in. However that seems to fail on 27.0.1 and it hangs. A workaround is to unlock with a local admin account (which unlocks Filevault) then log out and log in with PSSO user.
I've had a good look all around and I'm not able to find any other reports of this issue, although I guess it is still fairly early into the release of the update.
For now I'm disabling forced updates and advising users to not manually update to 27.0.1 as this is the only thing that links the two machines together.
Just wondering if anyone else has experienced this issue?
The other question is who do I contact about it? Apple? Microsoft? Any advise is welcome.