Can't send texts to one contact

[Upper_tanker]

Hey all. Just got my pixel XL 2 5 days ago. I text this contact right after I got the phone, and a few times between then and now with no issues. Today, I try to text her, and it says "sending" for a while, and then "message not sent. Tap to retry."

I've:
Made sure she wasn't blocked.
Tried with 4g on and off.
Deleted conversation and started a new one.
Removed sim card and re installed

I can call her and receive texts from her, I just can't text back. I haven't seen any questions like mine pertaining to the pixel 2 xl.

Anybody have any ideas?

 

[lunatic59]

Was the text only text or was there an attachment? I'm assuming you can still text everyone else.