Why will my Tracfone LG Lucky only text some contacts?

[AC Question]

I can call all contacts but only some texts will go through. I have tried data on with wifi off and any other configuration I can think of. I have also tried Textra as an alternative to the default app.

 

[the tall guy]

Hi, the numbers you are texting that don't work - do they have iphones? did you recently come from an iphone?