I have a 20amp circuit with a 20amp GFI and 4 more 15amp outlets after it. With nothing plugged in, they all indicate (on my 3-light tester) they are wired correctly. As soon as 1 thing is plugged in anywhere they all indicate an open neutral, including the starting GFI.
I have replaced the GFI, then the breaker with no change, I have inspected the line from the box to the GFI but no loose wiring. This circuit had been working fine using an 1100w microwave on the second outlet, occasionally using other small kitchen appliances here and the GFI.
The only thing new is we started running a clothing washer on the fourth outlet. It ran fine for a good month or so before this issue started, and it is running off a similar circiut just fine. So not sure if it is related or not. At a loss what to do, was going to pull breaker again to inspect connection and possibly replace again. Need suggestions.