You mentioned that it works fins on 4G wich would really indicate that this is an issue with your ISP trotthling your connection to the IPTV severs .. Meaning they reduce the bandwith to certain ip´s..
Did you try our free VPN ?
You can find it on your Dashboard
NEW VERSION IS OUT !
Uppdate to latest versin inside the app:
New TV Guide UI. Added Horizontal category view. Optimize loading time for Fire Sticket/TV.
Series info view's UI change
Movie info view's UI change
Upgraded Multi-DNS support from 3 to 5.
Multi location OpenVPN support...
well.. The main thing to get a good device for IPTV .. i always recommend Android TV os devices since this gives you so many option in terms of Apps you can choose..
So a Firestick or something like the Mibox S4 are great " cheap " devices ;)
Regards
@Sense