Сломалось на стороне Майкрософта, по всему миру, в сервисе Cloud Cache. Они знают и обещали починить. Кто не в курсе - родной Outlook Mobile сохраняет учётные данные на серверах Майкрософт, чтобы оно оттуда проверяло почту и отправляло пуш, когда появилась новая, это у них на сайте
документировано. Цитата:
Nino Bilic
Microsoft
Mar 28 2024 07:44 AM
@Ted_Mittelstaedt @dbkgict @Terrymmd91 @TimDJordan @mati5000 @Brianmsb @ceantuco @Peter2220 @Tonaco @dbran And anyone else asking about Outlook Mobile sign-in issues:
We believe that we have identified the problem causing this. It is related to a service side change that was just timed similarly to when release of on-prem updates were released but is completely unrelated to Exchange Server CU or SU updates. Rather, it is related to a Cloud Cache service side (see how this works here: Using hybrid Modern Authentication with Outlook for iOS and Android | Microsoft Learn). We are working with the relevant service team to address. We are still investigating the details of this but this would explain exactly what is going on.
https://techcommunity.microsoft.com/t5/exchange-te...
UPD 02.04.2024 пишут, что починили.