Hello Karel Grulich,
Thanks for your question
It may be a group policy.
Test the following. Verify that the ADSync service account is added for the following policy settings:
- Allow log on locally
- Log on as a batch job
- Log on as a service
The full solution is documented here as solutoion 1 in https://learn.microsoft.com/en-us/troubleshoot/entra/entra-id/user-prov-sync/services-sync-not-start#solution-1-set-user-rights-assignment-permissions-within-group-policy
Please let me know if that makes a difference.
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola