The B-Up Peanut Butter and Jelly Protein Bar is a great example of this. It's not that it tastes bad necessarily, it's just that the protein taste with the PB&J doesn't jive well together. It’s a little bit of an unnatural taste that doesn’t sit well on my taste buds. Again it's not bad, but not really a flavor I would get again. The jelly taste is a bit to fruity for this and should be paired back a bit more.
Not bad though. I could eat it. But not great.