The bedrock goes through layer -1 downwards

I made a copy of my world in experimental mode of the caves and cliffs part 2 and wanted to see what was below layer 0 and then I found that the bedrock went through layer -1 to layer -66 in the copy of my world in experimental mode this happened to me on 1.17.10 on android my device is Huawei P20 Lite, I hope they solve the error.