I had the same issue on my Android phone. I had roaming on, did restart multiple times, was connected to T-Mobile etc etc. I eventually realized under the network mode settings my phone had the "WCDMA/GSM (auto connect)" setting on, not LTE. Because ...
Today I noticed I am unable to send or receive texts. I logged on to my account and see the notice "Plan Expired". I'm on autopay and am usually billed every month without problem paid by cc. Just checked again now and the plan expired message is gon...