The info is at the tail end of another thread, but it's hard to find deserves it's own thread, IMO.
If, like me you've been waiting a few days for the excellent new VPN to return, I can confirm that the fix posted below works.
"For all of you who recently have issues with VPN in the developer version: Can you please go to the "Settings / Privacy & security" section, then in the Privacy section, click the button "Clear browsing data" then select only "Third party services data" and clear it? It should fix the issue for you."