I've been using Mullvad for ages (close to a decade soon) and never had an issue until sometime last year when I noticed that Youtube and Reddit (primarily, but other big sites as well) blocked most Mullvad IPs unless you were logged in to your Youtube/Reddit/etc account. Which is an issue for me since I use NewPipe for Youtube.
You have to do a lot of IP switching before you can find one that works so I gone so far that I disable the VPN sometimes for NewPipe on my phone.
I figured that the big tech companies where just having a crack down on VPN IPs and that's just the world I was living in now.
But since I already pay for Proton mail I figured I'd check out if there is a difference with their VPN. And I had no issues viewing Youtube with NewPipe, even with Proton's free VPN where I must assume the IP is flagged as a VPN all over the place.
Anyone can figure out why that's the case?
I don't know enough about networking, but for example, Proton blocks P2P unless you pick a specific server. With Mullvad it treats every server as a normal server. So there must be something different between Proton and Mullvad general setup?