I use Windows 10, so when dialing VPNs I opt for the Rasphone as it keeps the VPNs in alphabetical order. The Rasphone dialer started to take a very long time to open which was impacting my work.
The solution was this:
Open an elevated command prompt and run the following command:
netsh ras set tracing * disabled
Verify it with
netsh ras show tracing
You can also optionally clear down the log %windir%/tracing/rasphone_RASAPI32.log