The entity spawn group event listener does not get called when switching dimensions resulting in custom spawnable entities never spawning until minecraft is closed and re-opened in that dimension.
This was tested in my mod TakeTwoBetaMobs with the ShadowWolf entity and some debug print statements:
https://github.com/telvarost/TakeTwoBetaMobs-StationAPI/blob/main/src/main/java/com/github/telvarost/taketwobetamobs/events/init/EntitySpawnListener.java
The entity spawn group event listener does not get called when switching dimensions resulting in custom spawnable entities never spawning until minecraft is closed and re-opened in that dimension.
This was tested in my mod TakeTwoBetaMobs with the ShadowWolf entity and some debug print statements:
https://github.com/telvarost/TakeTwoBetaMobs-StationAPI/blob/main/src/main/java/com/github/telvarost/taketwobetamobs/events/init/EntitySpawnListener.java