Unable to get slimes to spawn

I am unable to get slimes to spawn in a slime chunks.

During my testing, I was unable to get slimes to spawn in swamp biomes too, even though the light level was under 7 (in the vanilla Minecraft server they would not spawn, but in singleplayer they did).

 

Clients tried: Feather Client (Fabric) 1.19 and Minecraft 1.19.

Server software tried: Pufferfish 1.19, Paper 1.19, and Minecraft Server 1.19. (No plugins)

 

Seed: 5635503605760614701

ChunkBase URL: https://www.chunkbase.com/apps/slime-finder#5635503605760614701

Chunk: 34 2 -36

Chunk coordinates: 547 11 -573

ChunkBase reports this chunk as a slime chunk.

 

Increased tick speed and tried in many chunks for countless hours but still refuses to spawn for some reason.

 

It could either be a bug with the game, with ChunkBase, or it's intentional, I'm just unlucky.