I've heard of PG allergies or sensitivities, but is is possible to have VG sensitivities? I ask this because I've had a few liquids that I've had to switch from a 70pg/30vg to 50/50. Since the switch I've had trouble taking normal full inhales when I vape, and have coughing fits. When I first started vaping, I used 50/50 blend without issue. Is there an adjustment period for this kind of thing that I'm just not aware of?