The bug

When multiple configured structure features with the same type are referenced in a biome's starts, only one of them generates. For example, it is impossible to have both taiga villages and desert villages generate in the same biome.

How to reproduce:

1. Download the attached data pack
2. Create a new world and import the data pack. It will replace the overworld with swamps and attempt to generate all types of villages in the swamp biome.
3. Locate villages at different positions with the following command:

   execute positioned ~3000 ~ ~ run locate village

Only taiga villages generate.
Note: in the pre-releases, the last feature of the same type would always generate, meaning that only plains villages would generate. This seems to have changed in 1.16.2, as I now only get taiga villages.