I didn't let it get that hot, though I let it get quite warm. Today, if when I get home it's still not dissolved, I will try once more, with some very hot water from the microwave. If that doesn't work, then I will just extract what I have with the syringe and try it out.
Try with really hot water from hot water tap. Too hot to put hand in but not boiling. Never had a problem and I use 1/4 tsp to 8 ml Of PG.
Sure your measurements were correct ???
J
GG stealth, Provari, iatty2, DIY chef