To change the licensing server, we have to run the following line in a elevated porwshell console:
iex “$env:windir\system32\cscript.exe $env:windir\system32\slmgr.vbs /skms kms.core.windows.net:1688”
Now we only have to wait a few minute and request a new license with the command slmgr.vbs /ato
That's it, as simple as that. Now our servers have a valid license again.
P.S. We are not sure if the cause of the issue is the change of datacentre, but for sure, using the right license server fixed the issue.