Thanks for this great info.
Discourse Comments used to work fine until we had a problem with Raptive (ad thrive updates).
The Discourse commenting settings are the same that you’ve screenshoted.
I enabled the custom fields are on a post. I don’t see any of the fields on a different post, but I do see the on the post in refernce. The wpdc_sync_post_comments was set to zero.
I’ll get the meta on a ‘broken’ post this morning.