@Vapez , I have the same experience and I have been vaping for two years now. After about half a tank, the flavour is gone. It's frustrating, but on the bright side, flavourless is way cheaper than buying juice or aroma. I have noticed though, that juices with higher pg% (60 and up), I can taste much better and longer. But high pg gives me other problems that I don't like to deal with.
Keeping hydrated makes some difference. If my mouth is really dry (which is almost always the case, due to medication) I can't taste anything very well. Drinking a lot and menthol flavours or gum help a little.
I have been searching for a liquid that I could use all day, but haven't found any that I could taste all day. It's the reason I never got a cartotank (cause what's the point), though I'm really curious how they vape.
Monday I'll receive the base I ordered and from then on I'll be going flavourless...Or maybe mixed with some menthol.