My house is from 1988/89 and I am having some GFCI related issues. The 3 bathroom outlets share a 15 amp circuit with the 2 outdoor outlets, outdoor lights, and several hall light areas. I realize this isn't up to modern code, but it's what I'm stuck dealing with. The 3 bathroom outlets and 2 outdoor outlets all had GFCIs on them, which I understand is not a great idea but they worked for the first 2 years or so. My wife recently has been having trouble using her hair dryer in the bathroom so I did some investigating. The dryer will not run in the outlet, but the GFCIs are not tripping since other devices will work without flipping any breakers or pressing any buttons after I try to turn on the dryer. My first step was to replace the standard breaker with a GFCI breaker and convert all the outlets to regular outlets. No luck, and now the GFCI breaker stays tripped. I'm confident I wired the breaker properly. I assume the fact it is tripped means it's trying to tell me there is a problem somewhere. I did notice while doing the outlet change that there is a 1v phantom voltage on one bathroom that shows up when the circuit is off, but I have no idea where that may be coming from. Any thoughts on what is going on here?