Dear
Your project is stood out to me because I have very similar experience of development with your project.
I have been involved in development for the IPTV Android app which run on Android TV box & FireTV stick.
I used the Leanback library and Kotlin language for it.
I can share the demo right now.
Also I have customized the IPTV portal based on Jellyfin open source streaming project.
I'd love to hear from you.
Best regards,
Poterasu