It appears that leaves no longer turn white during snowy weather, no matter how long you wait. This is not the same as my other, older bug report about switching dimensions, this is separate. I have Fancy Leaves on, aswell.

Steps to Reproduce:

1. Open a new world (existing ones probably work too)
2. Locate a snowy biome
3. Force it to, or wait until it snows
4. The leaves will never transition to white.

The attached image was me waiting in-game waiting for them to turn white while I was writing this.