I have my JellyFin on a dedicated server outside my home. I use a domain, with and SSH certificate. Before I moved to the domain and the cert I just had an IP:Port setup. At that time JellyFin worked perfectly fine with the windows app, but after moving to the domain and adding an SSH cert, it no longer wants to connect. It works perfectly fine in FIreFox though, so I’m curious if it’s worth trying to figure out why it won’t work in the app, or is using FireFox just as good.
The desktop app should have maximum encoding compatibility so you direct play. It’s not guaranteed with browsers e.g. I believe Firefox doesn’t and will never support HEVC.
My gripe with the desktop app is lack of ability to easily refresh like with a browser. The UI bugs out sometimes and I end up having to close and reopen the app.