There is a about 15x35 block area where i am not able to place any block. once i place them, they disappear right away and it doesn’t let me finish my house! i need a fix to this bug asap. thank you!

I can’t finish my house due to a random around 15x35 block area where i can’t place any block and when i try to, it disappears and it doesn’t let me build. I need a fix to this as soon as possible to keep progressing on my world.