10iii (no mobile data) - SMS "we will shortly be sending you a text with some settings." Text never arrives

Ever since I’ve had my 10iii i have not had mobile data (except possibly very briefly on the first boot).

If I look at the SMS log for my provider (Talkmobile), I have three text messages in a row stating:

“Wednesday, 27 July
From talkmobile: To use picture messageing on your mobile, we will shortly be sending you a text with some settings.”

“Sunday, 7 August
From talkmobile: To use picture messageing on your mobile, we will shortly be sending you a text with some settings.”

Today
“From talkmobile: To use picture messageing on your mobile, we will shortly be sending you a text with some settings.”

At no point have i ever received a text message with settings.
Might this also be related to my mobile data problems?

Related to this - but asking a separate problem: