We have a two family house. The kitchen faucet on the first floor occassionally bangs and no water comes out. The faucet has an aerator spray that is not used. Sometimes the faucet works properly, sometimes no water comes out.
This could be the diverter valve in the faucet that controls the side sprayer, or the washer in the on/off valve under the kitchen cabinet, or---something else.
Try working the spray head when the faucet is running to see if this isolates the problem.
Also check the piping under the cabinet to see if there is a branch pipe to the bathroom, or some other connection.
If there is a direct branch to the bathroom and the bathroom faucets are working ok the problem is probably in the kitchen faucet itself.
If you start to work on this, first stuff a rag or wad of paper toweling in the drain hole to avoid losing small parts.
Try shutting off the hot & cold on/off valves separately to see if this isolates the problem to the hot or cold shutoff valve.