Hi,
I just realized when placing pumps, previously placed floor tiles (cobblestone? stone bricks? not sure about the English name) are marked for deletion.
Can you fix that?
I am playing on 1.1 Experimental, with Krastorio 2 and Space Exploration and a few other mods that are suggested for that. I can't imagine those affecting this behavior in any way, but I can't rule it out either. It seems though that the removal is done on purpose, not as a side effect, as on and in a 1 tile radius around the items placed by PUMP.
Happy new year
Merikolus