Hi Ed! Good on you for using Proton VPN. I have used their email since they were in beta and love their privacy policy. Do you use them for mail too?
As to VPN usage, does Proton VPN allow you to force select your country you are routing thru? That could fix any language/measurement unit problems that arise (if your prob is indeed caused by that). I use Nord VPN and often country-surf just for the heck of it.
I am just going by stated policy re Google, Facebook, and the rest who actually come out and say that they harvest and sell private info. I have no prob with anyone who wants to do that, just that everyone knows what they are doing. Someone once said that if you cant figure out who is paying for a service, then the answer is that You Are. Google/FB/et al get a lot of money selling targeted advertising.