Background: I started my realm in 1.19.3 and killed the dragon before the update. After we updated to 1.19.4, we respawned the ender dragon and it did not create any new gateways. I fixed this issue by downloading NBTExplorer, navigating to [MyWorld]/level.dat/Data/DragonFight and then changing "NeedsStateScanning" from 0 to 1. I then had to kill two dragons. The first one did not spawn a new gateway, the second one did, and in testing in a creative world, any more dragons killed after the second also spawned a new gateway. It seems changing the NeedsStateScanning tag resets the counter on ender dragon fights, so the first one killed attempted to respawn the existing gateway (from our original fight), and the next 19 would spawn the next (non-existing) 19 gateways.
minigunman101
Background: I started my realm in 1.19.3 and killed the dragon before the update. After we updated to 1.19.4, we respawned the ender dragon and it did not create any new gateways. I fixed this issue by downloading NBTExplorer, navigating to [MyWorld]/level.dat/Data/DragonFight and then changing "NeedsStateScanning" from 0 to 1. I then had to kill two dragons. The first one did not spawn a new gateway, the second one did, and in testing in a creative world, any more dragons killed after the second also spawned a new gateway. It seems changing the NeedsStateScanning tag resets the counter on ender dragon fights, so the first one killed attempted to respawn the existing gateway (from our original fight), and the next 19 would spawn the next (non-existing) 19 gateways.