If you upgrade a world from a version prior to 1.18 to 1.18 or 1.18.1 the /locatebiome command can locate the wrong biomes in a specific condition due to the way Minecraft reports the biome.

In order to reproduce the issue it is needed to create a world in a prior version such as 1.16.5 and load into the world. Once inside the world to speed up the process render distance is advised to be turned to 32 chuncks in order to render as many chuncks as possible.

After a lot of chuncks are rendered the world can be upgraded to 1.18 or 1.18.1

At that point if the F3 menu is used to see the biome reported by the game if the chunck had been loaded and had an inahbited time value major than 0 it is correctly reported by Minecraft and by the /locatebiome (such as a desert will be reported to be a desert and found correctly by the command), however in the areas which have been rendered previously but not explored it can happen that the biome is for example a Taiga and is generated like a Taiga since it has already been rendered in the previous version, however Minecraft applies the new generation algorithms to report the biome so it is possible by using F3 while in the Taiga in the example that it is considered by the game a Mushroom Island, a Mesa ect... or the biome is reported correctly in the F3 screen but the /locatebiome locates the biome which would have generated in that location if the chunck had never been rendered.

Basically the biome is what it was in 1.16.5 but for the game its type is the one which would have been generated in 1.18.1 if the area had not been rendered previously. This causes the /locatebiome to report incorrect biomes.

Another side effect of this bug is that villages for example can be of the wrong type such as a plains village in the middle of a desert.

Attachment description: the screenshots are taken from a copy of the same world generated in 1.16.5. However in the screenshot 2022-01-09_12.14.45 the already rendered chuncks have been removed before upgrading by using MCA selector to show once they are re rendered what would the game have generated if the world had directly been generated in 1.18.x

In the screenshot 2022-01-09_12.10.54 the chuncks have not been trimmed so it is what the world goes through whenever a player updates a world to 1.18 without making any editing to the chuncks. The place is the same and as it can be seen even if Minecraft in this particular case reportes the correct biome the /locatebiome command is reporting the wrong biome.