yeah it happens. Especially if you drink hot liquids or alcohol. Try some cold water. And blow your nose. Remember to smell the vapor. A huge part of the flavor is in the aroma. That's why being in wind or having a fan blowing can mess up the flavor too. Your tongue can only taste sweet, salty, bitter, sour and umami (MSG). So a cherry eliquid will have some hopefully appropriate amount of sweet and sour on your tongue but it won't be cherry if you can't smell it. Food it the same way but food benefits from the look and feel too.
I vape a pair of flavors, one sweet (sweet vanillas like Backwoods Brew Vanilla Bean and Tasty Vapor Butter Cream) and one very non-sweet (Vapor4Life WOWbacco - like dark dark cocoa). I alternate vaping those and each helps refresh the other's flavor.
If you are vaping tobaccos, try some FreedomSmokeUSA DesertShip (70pg/30vg or 80pg/20vg) in a blank V4L carto. DesertShip has a strong smell (too strong for me to vape in the car or office). It is nutty and a bit pungent and reminds me and others of the smell of a freshly opened pack of cigs. And the WOWbacco is my current love. I swear that stuff has some TH even at 4mg in a standard res carto on a slim 510. I could not even inhale it at 18mg in a WOW cart which was why I started vaping it on the 510 instead. Something else I would do with tobacco vapes it stick some FreedomSmokeUSA Cocoa in the carto - that is pretty strong tasting stuff too. Most cigs have cocoa in them and I love coca in tobacco juices.
Something else that helped my taste buds - just changing up the flavor. I would often carry a tobacco flavor and two flavor changers - two of the following 3: vanilla, oRYental 4 (a sweet caramelly tobacco), and either chocolate or cocoa (cocoa if it was a sweet tobacco, chocolate if it was not, like DesertShip is not sweet). If the flavor gets boring, then mess with the flavor.