Just for accuracy, the query for the WAF exclusion is:
(http.request.uri.path eq "/posts(/[0-9]+)?" and http.request.method in {"POST" "PUT"})
You can copy-paste it if you click on the Edit expression on the left instead of using the form selection.
Noticed today as I updated and suddenly half the forum wasn’t working due to Auto Minify 
Edit: just noticed this is a wiki post. Silly me, I have edited the initial post.