The tub spout drips whenever there is water running elsewhere in the house. Kitchen sink, dishwasher, toilets, clothes washer... Once the water stops running the drip stops..?

I don't have a clue what to look for.

Mike

Any suggestions on what the issue may be? I have the same issue in my master bath. Thanks in advance!

That is an unusual problem. I would replace cartridge in tub faucet. Seems like the existing cartridge is not is not holding fluctuating pressure well. See if that helps

Milo