Are you actually completing the merge, or just previewing it? Previews don't give a reliable indication of the output when you nest fields as you have done.
I note, too, that you have a standard DATE field in your mailmerge main document. You should embed that in a QUOTE field so the date gets locked when the merge is executed; otherwise it'll update every time you open the output document, See
Convert Mailmerge Date Fields to Plain Text in the
Mailmerge Tips and Tricks 'Sticky' thread at the top of this forum:
https://www.msofficeforums.com/mail-...ps-tricks.html
While there, you should also look at the
Mailmerge Empty Line Suppression topic.