Steps to reproduce

1. Set time to always day.
2. Locate a mangrove swamp.
3. Make a grass platform about 30x30.
4. Fly up 25 blocks above the platform.
5. After 4 animals spawn run /kill @e so that you can watch for more spawns.
6. After observing animals for a while, cover the platform with lava and then make a stone roof above it several blocks up in the air.

Expected result

Only frogs spawn.

Observed result

Horses, llamas, armadillos, ocelots, pandas, and parrots spawn. In step (6) striders spawn.

Code analysis

In 1.21.50.20 Preview the following tags have been added to the data\definitions\biomes\mangrove_swamp.biome.json. These tags are causing the incorrect spawns.

"is_badlands",
"jungle",
"nether",
"overworld",
"savanna",
"spawns_warm_variant_frogs"