I'm not 100% sure, but I think quite a few of my bouts with VT were caused in some part by some of the clearo's I was using, as this was all very new to me I was sure at first what might cause it, however over the past month I have switched to some different type of tanks and some other types of clearo's, not the CE4's that I had before as they were going bad anyway and cannot be rebuilt, I found a few times that those CE4's were spitting at times and noticed that would actually kind of scorch some of the taste buds then the front part of my tongue would be sore, but since changing the type of clearos to TS3s and Protank, mini protank I have had less issues with this, but it's not 100% the problem, I also noticed that if I over vape certain types of juices causes a bit of sensitivity so I switch to Hazelnut, PB and some other richer type vapes, it seems to help lessen the issue quite a bit. That is just my personal observation and may not be the total answer but I'm not having the issue as much now thankfully.