After flushing toilet the tank didn't fill back up (last night). As I was running my bath this morning the tank started filling up & I shut the faucets off, tank filled up to water line & shut off. I flushed toilet & had to turn faucets in tub back on but didn't shut them off & noticed the water won't stop in tank @ water line unless faucets in tub are shut off.

Which type of fill valve do you have?