VAT number not displaying on a paid Invoice

I have sent one invoice that included VAT. At the time my account was set as "registered for VAT" while I waited for my VAT number. My invoice was sent, paid and bank statements matched.

I have now received my VAT number and updated my account. Now I need to resent the invoice showing the VAT. The paid invoice has automatically updated to show the VAT being applied, but the VAT number is not inserted next to the VAT label.

Creating new invoices are unaffected.