Tinnitus.
I've had buzzing in my ears for decades, but vaping PG made it much worse. It took a while to track down PG as the cause. I was surprised to learn that ENT doctors know about the PG causing/exacerbating tinnitus, and I've found several ECF'ers in the same boat.
After switching to VG nic base, it is back to the old level, or nearly so. It took 2-3 months. If I use too much PG-based flavoring, I have a fairly quick reaction, so I (DIY) vape with low flavoring and use non-PG flavorings when possible.
I to am experiencing the tinnitus symptoms from certain levels of PG. I find when I vape more then 50% or even 30% PG, my tinnitus suddenly becomes pronounced. As soon as the PG level is to high, it goes from years of it sitting in the background (hardly noticeable) to extreme and sensitive.