Go with Brave browser if you want to be the hippest dude on the block. (It blocks all the nasty by default so it's mighty fast). Firefox was acting up for me too, but now that Quantum's out it's a charm. You sure you're on the newest Firefox? Kudos for using Vivaldi. By the way Opera has built-in free VPN. I'm sorry but Chrome was never "good" - it has a wide open backdoor included in your installation. It's like handing your data over to Google on a silver plate.
I use dual-boot, it's great. It's not that difficult to setup actually, there are some nice tutorials online ;^)
The installation of Firefox I had issues with was in like 2016, and it was up-to-date at the time. I'd tried Vivalidi since it was an offshoot of Opera, for that exact reason - at that time, I didn't have my own full VPN (now I do).
I'm looking at Brave's site though. They've got some pretty interesting information - especially for the mobile version. While bandwidth isn't a huge issue for me because I'm largely homebound and on wi-fi, anything to make downloading faster is appealing - and having something cutting down on data does that.
Thanks!