Issue is seen with Citrix Virtual Apps and Desktops 7 1912 LTSR and with Windows Server OS VDA. When user changes the default printer inside the session to another network printer that is available, disconnect and then reconnects, the default printer is not the same. 
However if the user logoff and login back, the changes are retained, issue is seen only while the user disconnect the session and then reconnects. 

Set the below registry key on the VDA:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Print\Providers\Client Side Rendering Print Provider]
“RemovePrintersAtLogoff”=dword:00000000

This registry key is to help to retain the printers at logoff/disconnect. 
This registry key stops terminal servers removing session printers at logoff.



 

---

Problem Cause

Looks to be more of a OS behavior and profile related.