Hi Scott Lee
Based on what you're describing that the session host is not successfully reconnecting users to their existing disconnected sessions, or that user profile technologies such as FSLogix profile containers are not mounting correctly during logon. In environments like this, I would typically start by reviewing the active Group Policy settings that control session time limits, disconnected session handling, and reconnection behavior, as a misconfigured policy can cause the platform to launch a new session instead of reconnecting to the original one.
I'd also checking the TerminalServices and Remote Desktop Services event logs in Event Viewer, along with any FSLogix operational logs if profile containers are being used. These logs usually provide valuable clues regarding session state transitions, profile initialization failures, authentication issues, or profile disk attachment problems. Another useful step is to compare the disconnected session state reported on the host with the actual user session information returned by tools such as query user and qwinsta, which can help identify orphaned or inaccessible sessions.
If FSLogix is deployed, verify that the profile container paths are reachable, VHD/VHDX files are not locked, and that profile attachment is succeeding during sign-in. I would also review any recently applied GPO changes, especially those related to session limits, idle session policies, and "Restrict Remote Desktop Services users to a single Remote Desktop Services session."
At this stage, a structured review of Group Policy Results (GPResult), RDS event logs, and profile container logs would be the most effective diagnostic approach before escalating further. These data points usually help isolate whether the issue is policy-related, profile-related, or tied to the session host infrastructure itself.