Hey! I am having issues with custom cave generation

I am creating caves for a custom dimension in my datapack, but every cave below sea level is flooded with the default fluid and I am not sure how to fix this. From what I've read, it seems like aquifers may fix the issue, and I have aquifer generation set to true, but I do not know how to edit aquifer generation. If it makes a difference, the default fluid of my dimension is a solid block instead of water. This makes it look like cave generation completely stops below sea level like in the attached screenshot.