World does not blend when the new chunk is ocean and the old one is land

I've been trying to update my world for 1.19, deleting chunks (I used Anvil for the deletion).

All chunks blend propperly, except if the new chunk is ocean. In that case there is 0 blending.

Ive tried several times with diferent cuts. Land blends nicely or tries if the change is extreme. Water does not blend at all.