I’ve only got windows 10 on my laptop so I don’t think I can get the BT App on it. Also, I’m a Luddite so no idea what you’re talking about 50hz? Sorry;(Just had a look and it's a decent picture but it's 60fps which is causing stutter.
Try the BT Sport app because that is showing it at native framerate of 50fps and, if you can, change your device refresh rate to 50hz to match it.