I have had this problem in the past, but not any time recently. There was no real trick to it other than to put the device down for a while for me. Sometimes the flavour goes and sometimes the throat hit goes. I would try shaking your juices when you get them and then again every so often before
vaping or filling a carto/
tank. Depending on the manufacturing method of your
juice the flavour might be separating from the base a little.
Another possibility that I also experienced was how flavours just didn't taste the same to me any more and I had to search out some new favourites. A trick most people use is to vape a menthol if the TH disappears but in terms of flavour I can see how it may act as a palette cleanser if you will. Kind of like brushing your teeth after a meal.