Microsoft: September Windows updates break Always On VPN connections

Microsoft warned IT admins that September 2026 Windows 11 security updates can break Always On VPN connections, leaving them stuck in a "Connecting" state or showing a "The specified port is already in use" error. A temporary workaround is to switch the VPN profile from automatic protocol selection to a single protocol, either SSTP or IKEv2.

• VPN connections may stay stuck in "Connecting" or retry endlessly
• Repeated attempts can show "The specified port is already in use"
• Workaround: set profile to SSTP only or IKEv2 only
• Microsoft is still working on a permanent fix