There are 2 printer servers, each with 6 printers.

Apply the printers with Citrix policy "Printer Assignment".

If one printer server is offline, other online printers cannot be created in the ICA session desktop.

Please ensure the printers could be connected or remove the offline printers.

Problem Cause

It is the expected behavior.

The network printer creation is single threaded, the offline printers will block the printer creation. 

As the creation is single threaded, more offline printers will take more extra time to complete the printer creation.