I'm no fan of TH, mostly after flavor. I wonder, do you vape sweet juices? That aftertaste could be sucralose or some artificial sweetener. I get aftertaste galore from drinking diet soda, don't like it at all.
THIS! 10000x this! I recently switched to a mouthwash with no alcohol... and my tastebuds went to crap and my juices all tasted the same. Stopped using the mouthwash a couple of days ago and my taste is slowly coming back. That mouthwash was full of sorbitol and saccharin. Artificial sweeteners coat the inside of my mouth and never let go...