So I’ve found two issues with the /locatebiome command and I think they might be related.

The first issue is that I am only able to locate biomes that are relatively close by. In my case, I tried locating a snowy plains. It said it wasn’t within reasonable distance. I teleported 1000 blocks away and found it at about 4000 blocks from spawn. I think before it was able to locate biomes that were 40000 blocks away so it’s a huge difference.

The second issue: biomes at different heights are not located properly. In my case, I was in a cave, and I located a lush caves biome. 200 blocks away. Then I went up a bit, where the lush cave was closer at that height, and it said it was 3 blocks away (which I believe was accurate).