I have been travelling in and out of Thailand for 10 years now and have been preparing for the day that I move over there permanently (with my Thai wife of 9yrs). Of course, part of that preparation is making sure that all my ducks are in a row with documentation readiness when applying for a long term stay visa.
I have been following this group for years now to help with that preparation and understood that not all IO’s are on the same page as far as doc requirements, etc.
Your post has just shown me something completely new.
So I guess the lesson here is to carefully check the immigration office that one would need to use for future applications or extensions on their requirements so as not to get caught with your pants down.
You can go back into the TDAC that you completed and click the edit button. First check that your email address is correct and check all other details. If everything checks, then add a full stop after something and resubmit it. If you don’t get an email after that, then something is amiss.