I have a world that I made back in 1.16/1.17 (Cave and Cliffs features were on before the update) I have tried reloading the game, going to unloaded chunks and coming back. I have also tried going 1000+ Blocks away and quitting the game and reloading and traveling back through the overworld and nothing seems to work. Which is rather frustrating as I’m trying to explore new caves in my old chunks. In short the old bedrock layer from 1.16/1.17 (I’m not sure which I started the world on) is still there and has not be converted to deepslate after updating the game and making a copy of the world after prompted to do so.