On my samsung tv connected Roku thru my t mobile hot spot shows on tv but when a select a channel will npt connect.
May have to Edit your APN to reflect only IPv4 rather than IPv4/IPv6 or IPv6. On some T-mobile hotspots, you are not able to edit the APN, so you will create a new APN in the same configuration as the "Fast.t-mobile.com" or "mobile.com" APN except change "PDP Type" to IPv4 only. Make this your "Active" APN.
If you are using a 2.4ghz-only Roku device like the Roku Express (non-4k/4k+), or Roku Premiere (3920/3921), then you will also need to select the 2.4ghz band on the hotspot and change mode to b/g/n.
Feel free to post update or still need more help. Include hotspot model and model number of the Roku device (Settings/System/About).
You should also include the model number of your Samsung TV set. It should be found on either the side or the back of the set. I have a 1994 Magnavox/Philips TV set and its model number and other specifications are printed on a sticker label on the back; TS2756-C102.
~ Jordan