@Braguzz : Apologies for the delay on seeing/responding. Typically this has to deal with AD name collision and a forced DNS update.
You will likely need to do a couple things.
- Remove the new host pool VM from WVD and from the domain.
- Navigate back to the older VM. You may need to unjoin then rejoin the VM back to the domain so that the AD object and checked out IP address is updated.