-Are you in the UK or Abroad at the moment?
I am in the UK. Initially, I noticed it in France and thought it might be because of roaming but it's the same here
-Does this seem to happen on any specific dates or at specific times?
I have not noticed any date pattern. It always happen when I use some services (payment confirmation, etc)
-Does this happen with messages from any particular numbers or all numbers?
I "think" it happens with anything asking for some kind of confirmation.
I don't use SMS much otherwise so not quite sure. I'll runa few tests with family phones...
-Have you noticed any signal issues?
Nope
-If you remove one of the SIMs does the issue still persist?
Did not think of trying this. Will try
Another thing... I checked "Email me when someone replies" but did not get an email for your answer...
Is there something else I should do?
Thanks