Even after updating Citadel 2.4.5 to 2.4.6 or 2.4.7, the mod's biomes still aren't being generated.
I'm using a custom modpack I made with over 150 mods, but I'm not aware of any of them changing caves generation. Is the problem still being adressed? I can provide a list with all of the mods I'm using if needed.

I noticed this as well. World gen mods I had were tectonic, regions unexplored, river redux, biome makeover (RR and BM don't add too much content as far as non vanilla biomes goes so it's likely not them I'd assume, however both tectonic and RU do affect cave generation). Also The biomes do generate, just only under vanilla mc biomes and thus are often 5,000+ blocks away. Only adding this to save OP time if they happened to be using any of the mods that I used after updating citadel.

1. remove all mods but AC + citadel and see in a new world if caves generate

   2. slowly add in old mods to pack to find which mod is blocking generation this time

   3. report back on which mod that is

I just found out the conflict is with the RPG mod called Eternal Tales, too bad it adds tons of cool new stuff.

1. remove all mods but AC + citadel and see in a new world if caves generate
2. slowly add in old mods to pack to find which mod is blocking generation this time
3. report back on which mod that is

I have tested this too and yep, the biomes just don't generate. Even went into the configs to make them spawn more, no luck there either.

I can't find anything significant in the logs but in case anyone needs it, here you go: https://mclo.gs/GzFVQUp

I will be reporting this on ET's side as well, since it's not really clear if ET is stopping AC from generating or if AC is just incompatible with ET in some other ways