Do you still have this problem? I would first try restarting your device. If that doesn't help, move those buildings somewhere else temporarily and then move them back.
I'm having exactly the same problem. It's all in the NorthWest corner of my city. When new buildings get their first upgrade, the water gets cut off, showing a broken link to the water network. In some cases, it has been both the water and sewage that's cut off. It seems like the location is cursed, not the building. Any new building on the same lot has the problem.
A thought would be that not all water pumps are connected to the same roadsystem, I noticed trying to teach my niece and nephew that they built roadways that weren't connected. It's an easy miss...?
I'm having a similar issue. I had a shortage and decided to demolish aba doned buildings to bring the demand below the capacity, however it still showed a shortage although the capacity was above the demand. I even tried moving things around and restarting. No luck I even went as far as to demolish all the residential buildings and build new ones. They too became abandoned due to the water shortage. I'm at a loss and frustrated that I pumped some money into this game. Such a waste.
That is a common bug it seems. I would ensure the following:
I tried all that and since nothing worked, i just closed the app completely and just restarted, didn't see the error anymore.
Hopefully this helps you resolve the issue you are seeing.