How to make Piefed posts appear on Mastodon?

EDIT:

1. the Piefed post eventually appeared on Mastodon after ~1.5 hours. I don't know why it took so long when it's usually instant.
2. I "tagged" two user accounts in the Piefed post, but those user accounts appear as just plain text on Mastodon, so I don't know if those users have received notification.

I made the below post assuming it would appear on both the threadiverse & the "microblogiverse"(?)(Mastodon, Misskey, Pleroma etc), as I have seen other Piefed posts of mine do.

• https://piefed.social/c/neodb/p/1991127/can-a-neodb-collection-on-one-instance-be-seen-on-another

See other of my Piefed posts on Mastodon

• https://ohai.social/@klu9@piefed.social

But that post about NeoDB has not appeared on the microblogiverse. I thought the necessary element was Piefed tags, but it has those and hasn't appeared.

• Any ideas why not?
• Any ideas how to get it to show up?

Thanks