Plex video playback doesn't work in Vivaldi
Trying to play any video in Plex gives me a "There was a problem playing this item" message. It works perfectly in Chrome; user agent spoofing doesn't help; music plays just fine; Flash and Widevine are the same versions as on Chrome. Since Vivaldi is Chromium based, this is quite a weird issue and I haven't been able to find anything about it save for people having the same issue. I've asked on the Plex forums and subreddit with no luck.