Make sure that the following two updates are not installed on your PC.
KB5025305
KB5026372
Both of these updates are preview updates and should have been updated manually. If either one of them is installed, uninstalling the software may restore the situation.
The uninstallation procedure is as follows.
From Settings, open Update and Security → Windows Update.
Display update history → Open Uninstall updates in the upper left.
Please check if the above two updates are in the list. If there is, right-click on the corresponding update and uninstall it.
After that, restart your computer and try connecting to the VPN again.
Currently, it has been confirmed that some devices running Windows 11 are unable to connect to the VPN. Please try the following method as one of the solutions.
Caution
This setting seems to be possible only for wired LAN. Also, since it depends on the device driver, there may be some drivers that do not allow this setting.
This is a temporary workaround, so please restore the settings once the issue is resolved in your OS.
Open the control panel and go to Network and Internet > Network and Sharing Center > Go to “Change adapter settings .
Open the properties of the currently connected network device.
Select Configuration > Advanced Settings.
Please set the values of UDP checksum offload (IPv4) and UDP checksum offload (IPv6) to disable and try connecting again.
