Could be a few different things.
As menioned above its possible the earlier bottles of juice were better 'steeped' , i.e. had more time to blend properly and age and the newer bottles are fresher, i would start by (as mentioned above) uncapping it and letting it sit over night, to let any alcohol in the flavorings evaporate.
*EDIT* Now that i see its a much larger bottle and a tobacco it likely just needs more time to 'steep'/blend. Larger quantities and tobacco's especially benefit from sitting.
You can run a test, take some juice from the larger bottle and put it in a smaller one, like 10-15ml, then cap that bottle and put it in a bowl of warm (not hot) water for a few hours, shaking periodically, then test it and see if it tastes better. The heat speeds up the blending/steeping but its not really the ideal way to do it for all if, may just have to wait it out. A tobacco that tastes terrible on week 1 can be pretty amazing come week 3-4. Again, all just speculation, but worth a try.
Its also possible if you're in the first few months of vaping you could have vaper's tongue, which usually gos away after a few days.