So fiddling around on my test server, I gave myself bad omen, then I heard the horn from the raiders as the raid began, but the raid never started. (edit: By never started I mean, they bossbar shows up as the raid started, but the raiders never come to the village)
I then started to wander slowly around my village to see that a single pillager was floating a bit above the ground. As I moved closer to him he dropped and split out to 5 more pillagers (I'm assuming they were all spawned in one spot and frozen)
I came to realize they were stuck there due to entity activation range (mine was set at 26 for monsters)
Raiders tend to spawn more than 2 chunks (32 blocks, which is the default activation range for monsters) away from the player, so 32 just isn't cutting it, and it kind of disables the whole Raid feature of Minecraft.
Obviously I don't want to up the range for monsters just so raids would work, so my suggestion/question is, is it possible to add another "group" to entity activation range for raiders?
Ex:
entity-activation-range: animals: 32 monsters: 32 misc: 16 tick-inactive-villagers: true raiders: 64 // just a suggested default
This would give server owners the ability to deal with raiders differently than the rest of their mobs.
Thanks for reading