Checked on WIFI very good UHD quality.
I think T mobile somehow don't give you the speed showing you are on..
I can't watch YouTube vids even on 1440...while showing I'm connected at 5G and upwards of 400 Mbps...
Went into a TMobile store ,the rep couldn't connect his IPAD either to any UHD videos or even 1440..
ok. if its T-Mobile then you can try to bypass it by using a VPN.
even the Free ones should work.
try 1.1.1.1
https://apps.apple.com/us/app/1-1-1-1-faster-internet/id1423538627
If it gives you issues, you can open the app, tap on the the 3 lines on the upper right. it will open up extra setting in which you can just select "1.1.1.1" instead of "WARP" . Some sites doesn't work with "WARP".
you can also easily turn it off or on too from the app too or just leave it on all the time.
Once you have this installed and enabled. Then open YouTube and test out 4k over 4g/5g etc.
If this doesn't work you can try other free VPNS.
Proton VPN is the world's ONLY free VPN service that is safe to use and respects your privacy. Proton VPN is created by the CERN scientists behind Proton Mail - the world's largest encrypted email service. Proton’s free VPN offers secure and encrypted internet access with advanced security...
apps.apple.com
Windscribe VPN is a tool that secures Wifi and helps you safeguard your privacy online. Best part? It’s absolutely free to use and offers up to 10GB of bandwidth per month! That’s something you can actually use! With Windscribe VPN, you'll never mess with confusing settings and option menus...
apps.apple.com
