Idk how to explain it
I get what OP means. He/She means they have 87 sand eggs in their inventory and the egg extractor says they have 37 in their inventory.
Have you tried rejoining the server to see if the problem fixed itself?
I’ve be interested to see what would happen if you placed the eggs in your BH’s inventory into a chest or something, then put them back into the BH’s inventory.
It seems to have fixed itself
I’ve noticed this type of thing a lot with the Egg Extractor.
It’s usually not serious and only affects the display and not actual gameplay.
However, a more potentially dangerous issue exists when you try to extract too many eggs at once.
If your Blockhead gets tired or electricity runs out and you have to abort the crafting, you sometimes don’t get your eggs back. I believe I lost about 30 Red Marble Eggs this way. So now, I craft no more than about 10 at a time and that seems to avoid the problem.