The first step in fixing any problem is to reproduce it. If you can't reproduce it, any attempt to fix it will be futile, since you can't even test if your fix worked.
Get the login the person used when they had the problem and find a copy of the email to see what the values are set to. Always work on reproducing a problem before working on fixing it.
If you take your car to the mechanic because it won't start and every time they turn the key it starts, your mechanic won't work on the car.