I'm getting this same thing, i'm testing one VM and i am able to connect to it, when i have someone else try who is a entitled user for that VM, the connection fails, this is one VM in a persisteenr desktop pool.
Is there any news on this on how to fix this problem ?
This is a slightly different issue, once a user has logged in to a VM in a persistent pool, the VM is then exclusively assigned to that user. Since you have only one VM in the pool, and it's exclusive to your first user, the second user will not be able to connect to the desktop as there are no VMs in the pool free.