Factorio Forums

I used landfill on the water.

Thanks for the report.
This works as intended.
We don't want to do expensive checks for walls to update when tiles are being changed (through landfill or mod/script), so walls save if they were built next to water or not. You have to rebuild the walls to correct them.

I build them AFTER the landfill (entire green area was water )

Can you upload the save here, please?

Thats strange when I now break and replace them they are back to normal.