The hot water side of the fill valve pulses while filling in hot or warm settings. what could cause this
Take off the hot water hose and stick it in the laundry sink and see if the flow is steady, which it probably will be. If it is not the problem is with your hot water heater.
If the flow is steady it is likely the solenoid on the valve assembly is weak. Try replacing the valve assembly and see if that doesn’t fix things.