Unable to login using OAuth2

[mstimvol]

Hi, since yesterday we are facing issues with the auth_oidc plugin. Previously everything worked since months without any issue. But since yesterday, we're getting the following message in the logs:

Microsoft 365 Integration | API Error | Problem encountered getting a new token.: Array

In the configuration we are using:

https://login.microsoftonline.com/{tenant-id}/oauth2/v2.0/authorize https://login.microsoftonline.com/{tenant-id}/oauth2/v2.0/token

It seems that the error occurs when Moodle is doing the POST request on the token endpoint. We're facing this issue on different Moodle instances, some with auth_oidc, others are using the Moodle OAuth2 integration (see https://docs.moodle.org/501/en/OAuth_2_Microsoft_service) and all of them were working until yesterday.

Is anyone facing a similar issue and/or having additional information?!