EDIT:
In Windows 10 or 11, the way to get to the log is as follow:
1. In elevated command prompt, Type:
netsh ras set tracing * enabled
2. Try to establish the VPN connection
3. Stop the tracing in the elevated command prompt with:
netsh ras set tracing * disabled
4. Goto the %windir%\tracing folder using CD in command prompt and run:
netsh trace convert input=RRASEtwTracing.etl output=<output filename>.txt
5. The output file may contain the logging information.
ORIGINAL:
Ha, I did started with Windows 3.1 and I did get this one wrong.
Windows 11 had taken that option away. It is all in Event Log.
Without detail log, then the problem could be everyone's guess.
Uninstall WAN Miniport (L2TP) under Device Manager and rescan would be my next guess.
What would be yours?