Read through this thread here https://community.roku.com/t5/Wi-Fi-connectivity/Roku-not-connecting-to-T-Mobile-hotspot/td-p/786737.
For the TMobile hotspot devices, make sure you clone your existing APN and set the IP Protocol to IPv4 or IPv4/IPv6.
Roku devices will not currently connect if your TMobile hotspot device is currently set to IPv6 only.
Read through this thread here https://community.roku.com/t5/Wi-Fi-connectivity/Roku-not-connecting-to-T-Mobile-hotspot/td-p/786737.
For the TMobile hotspot devices, make sure you clone your existing APN and set the IP Protocol to IPv4 or IPv4/IPv6.
Roku devices will not currently connect if your TMobile hotspot device is currently set to IPv6 only.