Ruined portals generate floating in rivers instead of underwater

Ruined portals generate floating on water in any biome that is not an ocean instead of being submerged. I could not find a great example of this in 21w40a, but they can generate without even touching any solid blocks in wide rivers. 

Examples:

seed: -5122813796493059606

261 64 -14337

386 68 -22726

381 65 -31362

165 76 -36399

374 68 -62029