YouTube doesn't work on home Internet

Well I just tried to view YouTube on Wi-Fi from T-Mobil 5G home internet on IPad.

It just continues to buffer. But commercials load fast?

I have had the trash can internet for just over 1 Month here in Chicago and when I first started using this internet. I was ready to drop Comcast……but now I see problems.

At first You Tube was loading great. But in the past week I noticed something has changed in internet service from T-Mobile.  All other streaming services worked great and loaded super fast. But in past week NetFlix started to buffer also. 
I tried to contact T-Mobil….but one hour waits are crazy. So asked for return call but have had no reply in 4 days?  That's bad service T-Mobil!
I have rebooted system. I have reset trash can to factory settings. Nothing changed. I have turned off system for entire day to let it cool off. Still no change?

But when I reconnect to Comcast thru WI-Fi YouTube works again? 
I even tried neighbors WOW internet thru Wi-Fi and YouTube works great no buffering

It can only be T-Mobile internet. 
Only hope they read these to get some change?