problem with even battery discharge in jazz fender elite 5

[Andrew2901]

Good day. I have an important technical question for you. I have been using a Fender Jazz Bass Elite 5 bass guitar for several years and I have noticed a certain pattern. after removing the batteries during a break from work. [empty] After measuring the charge level, it turns out that one battery has about 6.5 V and the other about 0.5 V. This pattern applies regardless of whether I use rechargeable or disposable batteries. The question is: why do the batteries not wear out evenly? Do you think this is correct behavior? I would be very grateful for your answer. Best regards,