I'm using v4.0 with the Tmobile ROM variant and also the issue with Netflix. It's not showing up in the Play Store when I do a search for it or if I backdoor it by going thru an associated app the Play Store version will say it's not compatible and not allow an install. In the meantime until this gets resolved, would it be possible for someone to share their Netflix apk? Perhaps sideloading it will work?
Try using Magisk manager to hide Magisk root for the Play store. Clean the app data and setup again. Also sideloading the APK is ok as well. Just less convenient.