I've had this happen - at first I thought it was the juices, but I've come to find out that at times, I lose the ability to taste as well (weird to explain) but it's only temporary.
Some suggestions from other threads I've read
-Try a different juice (more potent for a while, menthol for example)
-Drink tomato juice
-Brush your teeth
I don't think it's permanant and I don't think it's the juice either. But, I don't know what juice you're talking about specifically so I cannot say for sure.
One example: I love chocolate flavored vapes. I have a chocolate covered strawberry I vape regularily. Just recently, it seemed weaker than usual and I was wondering why? Well, a short while later the taste returned with full effect. Ymmv but I found this to be only temporary.