Distributor: "There was an issue distributing the post" - few other clues

Traced back to wordfence issues. I'm going to close this off for now and resolve whatever is blocking things from wordfence, tks for listening! lol.
will post again if I hit new issues. tks.

@pbaddock could you provide more info on what you identified as conflicting with WordFence? I'm curious if there's a way for us to identify that or at least call that out as a potential source issue in our documentation... thanks!

I had setup the sites on ServerA, and then moved them over to ServerB as part of some re-organisation of the staging environments I had seutp. On ServerB I was simply getting that message "There was an issue distributing the post" without further details.

Eventually I disabled all wordfence setups on all sites and it started working.
I then re-enabled wordfence on the remote site (plan was to enable one by one to trace the source of the issue) but when I re-enabled again, things "just worked" as they were supposed to the first time.

So I am guessing perhaps some wordfence config needed to be updated or something on my site or were affected by the move, but after re-enabling it seems everything was ok. I had updated .htaccess also with the remote app authorisation code snippet so perhaps wordfence hadn't picked up on that. I'm sorry I can't be more specific helpful - to be honest I never really specifically identified the source, but instead found it started working above the above.