Changing the names of vanilla slices on "overloaded" files does not work.

[AsterIskBlooms]

When changing the name of a Vanilla slice (such as Middle) to something else (in my example, Coastal), it does not change it. This may be due to the large file size of my snowcapped file, with multiple custom biomes and lots of new slices.

[jacobsjo]

I cannot reproduce this in a new file. Please share the snowcapped file if you can only reproduce it with that. (Privately is ok, if you prefer)