The LVDA on DDC shows that it is not registered. When the user logs into the storefront, a new desktop will be assigned to them. No error message such as 'Cannot start desktop for this customer' is displayed.

Random VDI has its own session reconnection mechanism

The customer is using random desktops without power management, so this behavior is by design. If the VM remains in an unregistered state, a new desktop will be assigned to the user upon their next login. 

Random desktop reconnection logic is not same as the dedicate VDI