That happened to me and it was the nic level was too high. Once I did something about it, it took a while to get back to normal.
One thing that made a difference for me was being careful where the vapor "hits" in the mouth. I was sending warm vapor right on my tongue which tastes great but, oof, it eventually scorched my tongue and knocked out my taste buds for a while. I'm careful to move the direction of the vapor around often now.
I'll have to try to be more careful where the vapour hits as the burnt tongue was no fun and made eating a chore. Thanks for the reply.