Flavor Evaporation?

[ShaSha]

I think I am stuck in rookie mode for awhile & maybe this post should be in a different section so I would appreciate some schooling but at this moment I am curious if my flavor can evaporate?
I have a friend who makes me base of 50/50 @ 18mg level so I can simply play with my flavors - using Flavour Art banana 1.25 ml & apple 1.75 ml - making a 17 ml bottle. I've let it set, uncapped since Saturday afternoon. I just went and dropped a couple drops on my tester tank & NOTHING - well almost nothing - maybe a hint of thin Vaseline but barely - WHAT DID I DO ?
My last attempt with this process was caramel & RY4 - delicious! Is there a trick w/ fruits I'm missing?
every tid bit of advice will be noted & taken to heart - THANK YOU IN ADVANCE!!

 

[Ahoy]

What's your base nicotine strength? Is it PG based or VG based? or are you using unflavored nic and just using pg and vg? I make watermelon all the time and its my ADV pretty much, I do about a 25% blend for fruit flavors.
Also, sometimes the flavors from certain vendors just don't taste good..taste is subjective. I think TFA's cheesecake is disgusting and tastes like cheese pizza - others love it. So maybe, if all else fails, try a different vendor?