I have a small but also very big issue. This issue first appeared in 1.19.81 when I normaly joined my in Update 1.16.2 created world and in the far north of my world there were suddently these weird chunk generation errors. I don't know what to call them but they reach higher than y200 and go as far down as bedrock with lava lakes on top of the bedrock layer. I suddently had these chunks in the far south of my world.

The attached screenshots are from the chunks in the north. But I encountered the issue in 1.20.1 in the south of my world. Thats why I am reporting it right here. I don't have screenshots of the chunks in the south since I was able to fix it after I deleted the world and copied it 2 times, on the third world copy the issue was no loger present.
The chunks in the south looked similar to them in the north with the same generation (Normal Biomes sudently cut from the existing chunks elevated up to y200 and higher, most of the time with oceans on y70-80 and lava lakes at the bottom of the bedrock layer, also with huge ravines in the middle as you see in screenshot 90)

I don't have steps to reproduce it since it apeared out of no where when I joining my world as usual and I only know how to fix it. Have copys before you join a world. If you have the issue leave and delete the world you joined. Go make a copy of the copy. Join the copy and if the issue still apears repeat until it is no longer happening.

IF this bug report should already exist in any way. Sorry for reporting it again. I checked before I created this report. And I didn't find anything related to my issue.
My world is roughly 550Mb in world size. Maybe that is the problem. I don't know.

Thanks for viewing my issue. And please don't close it right away with resolved or can't repeat.