This is on Xbox One Minecraft Bedrock Edition  version 1.17.10. When creating a new world with the caves and cliffs experimental feature checked, the starting chest when active does not spawn. Created 3 different worlds and was able to reproduce that bug. Also very few cave openings in the overworld. The few that did spawn were all flooded. Had to dig over 100 blocks to find a cave. There are also no ravines that are accessible from the surface. Iron ore is also incredibly scarce. The 3 seeds that were created had all of the bugs stated before. Unfortunately I deleted all the worlds out of frustration.

Edit: Made a new world. Still has the same issues stated above. The seed is: 1923151483