UDP is throttled to about 100 kbps on T-Mobile. Wireguard won't work and TCP based VPNs don't work either because the carrier injects TCP RST packets to all VPN-like connections.
Is this a regional (or plan-related) thing? I have no problem hitting 200Mbps to my wireguard server at home, though I'm on one of the old Simple Choice plans (with the Binge-On throttling disabled if that matters).
Sounds like it's time to get a new ISP. "We won't let you use our network unless you let us look at the traffic" is a pretty clear message to me.
It actually depends on the city. In certain parts of Chicago, what you say reflects my experience, but I haven't run into those issues in most places.
On T-Mobile LTE. Just connect to VPN using NordLynx which is wireguard. Speed test show 16Mpbs down so...
I must clarify this because you're right. I checked with my buddy on T-Mobile that has a Wireguard VPN and it works fine. I think it has to be an MTU setting that needs to be changed. Or it could be a geographic block but I find this theory unlikely.