[Bug] Ghost pumice (and only ghost pumice) on a server

[Pentigan]

Error Behaviour

I've got a server (1.21.1, Neoforge 21.1.209) with a big custom modpack including Caupona (0.5.2) with its default config options and I've set up what I believe to be a functioning pumice bloom fumarole: Lava two blocks under the fumarole block, water pool surrounding the block below the fumarole.

It only generates client-side 'ghost' pumice blooms, the kind that can't be broken but vanish instantly when right clicked. It only generates ghost pumice when a player is nearby, the chunk simply being loaded doesn't cause any to appear, when chunk loaded but without a player it simply doesn't generate anything at all. This has locked out the entire Felsic Tuff, Opus Incertum and Opus Recticulatum block sets from being craftable.

Expected Behaviour

For the fumarole to generate pumice blooms as intended and to not generate client-sided ghost blooms.

Reproduce

1. Run the noted version of Caupona on a dedicated server.
2. Build the pumice generation setup as noted in the report and implied by the guidebook.
3. Check whether generated pumices are real or client-side ghosts by attempting to break and right click them.
4. Further, force-load the chunk and see if it generates pumice when the player is not around.

Crash Report

No response

Mod version

0.5.2

Server version

1.21.1, Neoforge 21.1.209

Other mods and plugins

I don't have an easy way to quickly note down all 179 mods and their versions in the pack so I've just included a pack export. Hopefully the problem is evident just with Caupona but maybe one of the other mods is to blame.

Machina Marginalia-2.52 Githubber's Edition.zip