Text messages blocked

Same problem as others have mentioned.  iPhone stops receiving texts from Android devices - VERY frustrating when it’s a verification code needed to log into a website-and sending texts, noting “Free Msg: Unable to send message- Message Blocking is active”.  After being transferred to tech support and resetting network settings, it might be fixed.  Extremely long waits to get help - have previously been happy with T-Mobile services but this has now happened on all three of our lines.