Unable to authenticate to log in from lock screen when on VPN?

We have a user who works remote that is unable to log in from the lock screen if they are connected to the VPN. This only occurs for this one user, and they can log in fine if the VPN is not connected. Once the screen locks, the machine needs to be rebooted before login is possible. I cannot reproduce the issue at all, but i can see the security audit failures when he tries to log in with the proper time stamps.
This is with built in Windows 10 VPN. I have tried with both IKEv2 and SSTP but both have the same issue.
I have found posts similar to this online however there is never a solution for the issue. Does anyone have any ideas or hints of where to look for what is causing this?
Thanks in advance!!!
The error message received is:
The password is incorrect. Try again.
Have tried with his domain account. Will be making him a new local account in about 10 minutes to try this as a workaround. Hopefully this works because I cannot seem to find any kind of reason for this to be happening, its only for this one user.
Just want to confirm the current situations. Could new local account be work?