Allows placing pumps inland if any "waterfill"-type items are unlocked
Providing the player with new tools or adjusting the game interface, without fundamentally changing gameplay.
the pumps wont attach to a pipe that's already placed
Are you using AAI Industries? That might be the same problem as this one: https://mods.factorio.com/mod/inland_pumps/discussion/5cbd2e652b2f55000d29f260
I think it is, but it doesnt say how to solve it