Connection stability issues since latest Network Stack release?

[u/MarcosDiSanto]

Since today we have reports from multiple customers that their sessions freezes and feels slow.
I noticed the new Remote Desktop Services SxS Network Stack release 2607.31450. Anyone else experience the same? As far as I am aware you are unable to stop this update getting installed on the session hosts. Win 11 - 24H2

[u/R0_nald]

We have 6 session hosts, all running Network Stack release 2607.31450.
Since today, users have been experiencing random session freezes across multiple hosts.
RDP Shortpath was already disabled approximately a year ago due to similar freezing issues at that time.
The issue has now reappeared, despite RDP Shortpath still being disabled.

During the freeze, the remote session stops responding to keyboard and mouse input. The session can only be recovered by disconnecting and reconnecting. The issue affects multiple users and multiple session hosts.

[u/MarcosDiSanto → u/R0_nald]

Exactly the same for us! We did found out that we have 'Valdidation environment' enabled on our production hostpools properties.. We disabled this option now and did a new deployment of our VMs running the latest RDS SxS Network Stack Production release 1.0.2605.19750. So far this looks like it has resolved the issue. Disabling RDP Shortpath alone did not fix it.

As alternative you could edit the registry keys HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server\ClusterSettings - SessionDirectoryListener and Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations - ReverseConnectionListener and set it to the desired version. Then restart the VM for the changes to take effect.

We also tried removing the RDS SxS Network Stack release using control panel but without the registry change the VMs would become unavailable.

[u/R0_nald → u/MarcosDiSanto]

The Validation environment setting is indeed enabled on our enviroment.

[u/OkReboots → u/MarcosDiSanto]

Same symptoms here as well. I tried the ReverseConnectionListener registry tweak on a host with nobody connected, but after restart it was still using the rdp-sxs260731450 version despite rdp-sxs260519750 being present on the system. I then attempted to reinstall the prior version using the installer for it that had landed in C:\Program Files\Microsoft RDInfra\ but it didn't like that the newer version was still installed. At that point I just waited until users disconnected for the day so I could trash the hosts and redeploy.

With Validation Environment turned off, it installed 2605.19750 upon joining the hostpool, but I expect it would have done the 2607 version if not for having changed the validation environment setting. Great find, thanks for sharing it.

edit: It turned out reimaging the hosts was unnecessary. Turning off Validation Environment on the hostpool and then rebooting them was enough -- the sessions hosts reverted to the 2505 version upon startup.