Certificate errors with Microsoft 365 accounts

[iphoneuserinyyz]

I have been experiencing recurrent problems on iOS and iPadOS for all my MS365 accounts (which I have deleted and re-set up, to no avail).

I keep getting a popup like this:

When I click on "More Details", I see this:

When I check on the list of Apple trusted root certificates (https://support.apple.com/en-ca/HT213464), I see that DigiCert CA-1 is not on the list). Could this be the source of the problems? If so, is this something I can fix on my end? If not, is there any other way to fix this?

 

[WorldIRC]

Happening to me and all my coworkers too. Our IT company advises their other clients are also complaining. They have a ticket open w/ Microsoft for this.

 

[iphoneuserinyyz]

Happening to me and all my coworkers too. Our IT company advises their other clients are also complaining. They have a ticket open w/ Microsoft for this.

Knowing that the problem is widespread is kind of a relief - it has been driving me bonkers.

 

[WorldIRC]

Knowing that the problem is widespread is kind of a relief - it has been driving me bonkers.

What isn't confirmed though is if the issue is with Microsoft or Apple.