Is there a way to fix MCC tool chest world converter's rendering glitch?
Bedrock and Java edition has different chunk generation, so you could find something like this:
After you cross "border of your bedrock world" generation will be normal, but for java edition - it can't generate your old bedrock anymore, even with same seed.
There is a small chance, that you put your world somehow to amplified version, but unlikely. It would look like this and this.