siri response sorry your message was not understood

iPhone 5S IOS 10

I am trying to use Siri to send a text message. Each time that I do, she accepts it and even says sent. I then receive a text message from 662-453 stating "Sorry, your message was not understood. Please try again".

When I go to the message conversation area, every message I sent is in a conversation

to _$!<mobile>!$. It does not matter who I am sending to, these two items occur.

I reset "all settings" and it did not fix it. I also performed a soft restart by holding the home button and the on/off button simultaneously and then reset siri to reactivate siri.

Is this a problem with IOS 10 since I googled this problem and others are having the same problem but only started happening after IOS 10?

Thanks for any help.