Issue: Clicking on a video in the Patreon app opens the link in your browser instead. If you are not logged in there it won't let you watch the video.
Solution: Log in to your Patreon account in your browser to watch the video (I tested it on Firefox and Chrome so if you're still having issues try those).
Alternatively: Just skip the Patreon app and use Patreon directly in your browser.
Sadly I can't do anything about this, it's just how Patreon handles it >.< I can't use the inbuild video solution from Patreon because it is strictly SFW only :(