For the benefit of people with the G string problem on the 5-string bass. After several discussions with the guitar shop owner (trying to understand why there was this issue), we solved it easily. First of all, this issue affects only the 5 string. And only the p-pickup. The 5-string has an odd number of strings, so the split pickup should take care of the first 2 strings with one side of the pickup and 3 strings with the other side. The reason why the G string has a lower volume is because it has been switched with the p pickups, so the side with two strings to take care of has 3 poles and the side with 3 strings has only 2 (resulting in the G string without a proper pole associated). To solve it, simply switch the p bass pickups, and you will be fine. You’re welcome.