MTD module - VAT return not showing as submitted in Sage 50 Accounts

SOLVED

I've just submitted my first VAT return using the new MTD module following the knowledge base article 41955 https://ask.sage.co.uk/scripts/ask.cfg/php.exe/enduser/std_adp.php?p_faqid=41955 . 

It submitted okay and shows as submitted if I log in to my Government Gateway account, however on Sage 50 Accounts (v24.3)  the return is not shown as Submitted.