Incremental builds seem to be using two competing caches

Our Gatsby site pulls content from WordPress. We have a new page that is leveraging WordPress comments - each time a new comment is approved a build is generated and a new block (with the new comment) is added to the page.

The problem is that other incremental builds not triggered by this page or new comments are constantly changing this page. The page is supposed to have 9 comments on it like this Wisconsin Wall of Wisdom | Wisconsin Alumni Association
But every other incremental build reverts to a version with only 4 comments on it like this
Wisconsin Wall of Wisdom | Wisconsin Alumni Association

Both the “4 comment” and the “9 comment” incremental build logs show the line

Found a Gatsby cache. We’re about to go FAST. :zap:

It’s like there are two different competing versions of the cache that the site keeps ping-ponging between.
None of these builds show any information acknowledging that the page in question was changed.

Any ideas on how I can troubleshoot this further? This is a high profile page for the next few days, and we are starting to get a lot of flak for this problem.

Additional info: we did a full cache-clear rebuild at 12:06 today which fetched 4 Comments, and then another at 1:58 which fetched 9 comments. I would think the most recent one would take precedent, but again, it seems like perhaps there are two different caches being referenced(?)