What juice are you using? mg/ml?
Can you taste it first thing in the morning?
I'm in flavour heaven until I have my coffee, then it gets masked and lost in my mouth.
I tend to get the flavour back after a few olives and a sip of water...if only for a few pulls.
I also find if I chain vape on one device for too long I loss the depth of flavour in the juice. I will switch devices or drop to a simple tobacco juice for a bit to reset my palate.
Also heard that pulls on the left side of the mouth/tongue are more flavourful. (I vape left handed and don't notice a decrease when using the PV straight in or on the right....

)
Good luck
I