I had something similar happen with my game. The characters my group played at the end of the play-test carried over into 5e once it was released. These players were all new to D&D. After a few sessions, I noticed that they weren't all really playing their "builds". I allowed each player a chance to "rewrite" their character. The cleric changed domains from life to war (he rarely healed, and preferred melee), and the wizard switched to a sorcerer. Both were much happier after the switch. No in-game reasons, we just retconned it.
About six months later, the rogue player felt the same way, but instead of a rewrite, retired her character and replaced her with a monk.