Nether from 1.12 has no Fortress Mob spawns in 1.13

We kept our 1.12 Nether, and went to 1.13, everything else got deleted. The Fortress' in the nether do not work do not have any spawns. Ghast spawn, blaze spawn in blaze spawners but not in the fortress, zombie pigmen spawn, have refreshed the server, moved it to another server, /difficulty peaceful /difficulty hard. Been the only one on, and nothing.