502 error when combined with content-heavy ACF pages

[tcmulder]

We're getting a 502 timeout error when saving posts that have a lot of ACF fields on them, causing the content to be partially unsaved (i.e. some fields that had content further down the page are empty once we refresh after the 502 error). If we disable WPGatsby, these same posts save quickly, even if we double the number of ACF fields on them.

For now, we're disabling WPGatsby, making a bunch of changes, reactivating the plugin, then saving a post that happens to have only a few ACF fields; when we do this, everything works great and our Gatsby site updates with all the content correctly.

So, it seems WPGatsby is maybe doing something expensive on post save when many ACF fields are present.