I am deploying some WVD host-pool session-host VMs.
While doing that, only few of the machines are joining the domain successfully, the others are failing (timeout while waiting for JsonADDomainExtension) and thus the entire deployment fails.
After the failure, logging in to the joindomain-failed machines shows they had successfully joined the domain, and JsonADDomainExtension log shows it finished running after about one minute.
Because some machine joins successfully I can rule out network issues and credential issues. The user's MachineAccountQuota is set to 15000 - so that is not the problem as well.
The time is set to the right time, also - it seems like the machine is actually joined successfully and the problem is Azure reading that state. It looks like when I'm reseting the password using azure Password Reset blade machines that were stuck on joindomain phase will finish with this state and become ready