Hi Ron Downey,
Your reluctance to make a global FSLogix change immediately is exactly the right instinct. You have hit on one of the most notorious architectural trade-offs in Azure Virtual Desktop (AVD) environments.
You are absolutely correct that many older Microsoft and community references suggest roaming the Microsoft.AAD.BrokerPlugin directory to preserve Office 365 Single Sign-On (SSO) tokens. The goal of roaming that folder is to prevent users from being prompted for credentials every time they land on a new session host.
However, here is the technical catch: The Primary Refresh Token (PRT) cached inside that broker plugin is cryptographically bound to the specific hardware ID of the VM where it was originally generated. When FSLogix roams that exact cache to a different session host in the pool, the hardware mismatch instantly invalidates the token payload. While robust applications like Outlook or Teams can sometimes gracefully recover by silently requesting a new token, background system services like Universal Print fail hard, resulting in the exact 0x8001012d OAuth deadlock you experienced.
For your upcoming testing phase, here is the modern best practice to evaluate:
Instead of using FSLogix to brute-force roam the broker plugin, ensure your AVD host pool is properly configured for Entra ID Seamless SSO (or that the hosts are Entra ID Joined with Azure AD PRT functioning at the machine level). When Seamless SSO is fully functional, you can safely exclude the Microsoft.AAD.BrokerPlugin directory in your redirections.xml. Windows will simply negotiate a fresh, healthy, hardware-accurate PRT during the user's initial logon process on whatever host they land on. This satisfies both Office 365 activation and Universal Print authentication without causing cross-host corruption.
I am glad we were able to pinpoint the root cause of the missing printers! If the targeted cache cleanup successfully unblocked your deployment and proved where the fault lies, please consider clicking "Accept Answer" on the previous response so other AVD administrators wrestling with Universal Print token issues can find this exact solution. Let me know how your SSO testing goes!