I was trying to upgrade my Magical Snow Globe by trying to get all the different biomes on it, when I tried to change my biome it would not change, it said in the chat window that it changed the biome, but when you use F3 to see your biome is just shows my default biome as Plains. Not sure if this is intentional or a bug.
Yes, I did try different biomes, but it still didn't change, surely it won't affect your quest book but may affect your game experience when trying to be in those specific biomes to upgrade things such as your magical snow globe to have 7 different biomes. It's not something that requires urgency but rather just pointing out that a feature that is available isn't working as likely intended.
The intended method was either to walk around your stoneblock until the biome changes, not really possible given the size of the islands. Or visit the appropriate biomes such as Hell and End in their respective dimensions and visiting the Deep Dark to collect the vanilla biomes you need for the snow globe, you can also use the terraformer to change your biome as well, but this would also require a visit to the Deep Dark or similar dimension that has all sorts of different biomes.