RE Postscript
This issue has been resolved.
This is a Spigot server issue and works fine on vanilla servers.

Postscript
The MC-234767 report was created by me a long time ago.
On the other hand, this report, which is open now, has been reworked and updated, so please see here instead of MC-234767.

I can't speak English.

If you try to explode a soul sand and an ender pearl floating in the water with TNT (TNT Cannon), it will normally be blown away in single player.
But in multiplayer, it's abnormal and doesn't fly in an explosion, nothing happens. Please fix it so that it will be blown away even in multiplayer.

I want you to explode correctly in the water and knock back.