Nether laggy

Status
Works as designed
Issue description

I don't know why but my Nether is very laggy, I can't hit mobs, they don't move, SOMETIME mobs don't even spawn{not peaceful}

I don't know if because custom mobs spawn in Nether

It can't be structures because structures because it was laggy before I add structures

But I need help about this

Issue comments

This could be due to RAM limitations. If this is not issue in actual Minecraft, I would this consider normal.