I have an Epiphone BB King Lucille.
When switching from 1 pickup to the other the volume is drastically different. With both Volume and Tone Knobs set to max Rhythm is at a normal level but when you switch to Treble you can barely hear it and have to crank the amp right up.
The guitar has 2 output Jacks Mono and Stereo. Mono is supposed to be Neck and Bridge whereas stereo seems to be only Bridge pickup.
I am using the Mono output when experiencing this issue. If I move to stereo it does the same but opposite pickups.