I went through the same thing a while back.
While patience is a good thing, so is tasting your juice, the two work in opposite directions here.
What helped me out a bit was to hit the vape right after a sip of water. I don't know why this worked for me, however it's been extremely handy since. In my experience ice-cold worked the best.
I think that in some ways it may be related to your mouth adapting to the flavor and taking said flavor as a "baseline" at which point you can't taste anything but something other than your juice. Another way to look it: If you sit down by a campfire, you smell the fire. Sit there for a couple of hours and you can't smell the fire any more -- your nervous system has adapted to the smoke particles and while you can smell the lack of them, you can't smell them directly. I would postulate that the same thing happens with taste as well.
Much like tasting food products professionally is concerned, something to "cleanse the palate" may be in order. For me, that happens to be extremely cold water, give it a try. The most you'll get is more hydrated, which isn't a bad thing. (doubly so as hydration is key to taste in the first place)
Edit: Since taste is a chemical reaction, and despite a great deal of flavored juices, the primary chemical of the juice is the same, I'd think it possible that your taste system is whacked out by the constant assault of PG/VG resuling in a taste equivilent of a false-normal because of the PG/VG. This also works with the concept of flavors coming back in over time.
