Hello everyone! I've started vaping again and because I live in Mass have been getting unflavored nicotine and mixing it with menthol flavor from Amazon, brands vary but always pg based. I've never had any issues until today when I went to refill my tank and found chunks had formed. I made another batch and within an hour it too had gone chunky. The flavor and nicotine still in their bottles are normal and the juice in my tank is normal. If I can put a pic with my post I will. Feel free to ask me any questions if you need more info!