Liquid disappearing with nothing pumping it.

For me, your save worked perfectly fine. Water dropped down then moved to lower density tiles. (v208196)

loading seems to fix things for a while but weird pumps behaviour just jumps out of nowhere. Perhaps disabling and enabling the pump sometimes doesn't propagates the state correctly.

With low room pressure, pumps can create a vacuum tile that stucks there until reload and destroying water.

There is/was another bug when pumps lost status details and just pumped in water at max speed without outputting anything. (this may be fixed in v208196)

4 minutes ago, Blas88 said:

There is/was another bug when pumps lost status details and just pumped in water at max speed without outputting anything. (this may be fixed in v208196)

It's not, seen that today too :-/

Would appear to be a case where the pump's element consumer was still registered on the SimDLL.
Possibly orphaned?