It looks like KB5066198 introduces SMB2 regression on Windows 10 pro and home (confirmed on 3 machines).
Prior to this update, connections to an SMB2 share on an ASUS RT-AX86U Pro router were stable and maintained for a very long time. I verified that using netstat on the router.
Since installing the KB, and only this KB, connecting via Windows CLI/Apps/File Explorer failed on the first attempt. E.g., the File Explorer shows the “Windows cannot access NAME-OR-IP-BOTH-FAIL/Folder” pop up message. “Insisting” – i.e. retrying – 5-12 times eventually gains access to the shared folder.
When a connection is finally established, it drops after ~10 seconds. Confirmed with netstat on the router and with getting the pop up again.
The share is SMB2 only (My understanding is that the router does not support SMB3).
I have verified that on the Windows machines:
SMB1 is disabled
SMB signing is off
Multichannel is off
The Dialect is 2.0.2
The behavior occurs both using the server name and direct IP.
This did not happen before KB5066198. I suspect the update introduced a regression in the SMB2 client stack affecting session persistence.
Has anyone else seen similar behavior? If so, have you found any reliable workaround that doesn’t require uninstalling the KB?
Thank you.
