Sadly, I wasn't able to get a screenshot, but when I loaded up Bedrock edition on my PC (Thank you for fixing the launcher bugs with this btw) I spawned on top of a hill, and upon seeing a nearby shipwreck (only a couple blocks away) I saw an achievement pop up on my screen saying, "Advancement made! Explore 17 biomes". My render distance was set to somewhere between 8 and 16 chunks (computer is getting worked on, so I can't double check), and I technically had only been in a hilly plain and an ocean biome, without setting foot in any other biomes. I hope I have provided enough information, but once I get my computer fixed, I will clarify my render distance. I hope this helps!
Steps to reproduce:
1. Load new world
2.Set high render distance
3.Walk around a little to load distant chunks
Expected Behavior:
Player should need to walk into each individual biome to have properly 'explored' it.