This was actually why I stopped reading Xanth. I started in my preteens (and I don't think they do much harm; at that point, most of the unpleasant stuff just goes straight over one's head.) When I went to reread them in my later teens, I was appalled to realize that "A Spell for Chameleon" and, moreso, "The Source of Magic" were just extended jokes about PMS, at which point I stopped being able to read any of the Xanth books without seeing unpleasant sexist tropes everywhere. (Chameleon had previously been my favorite character, specifically her ugly and smart personality, which I was forever hoping would become locked in as her obvious real identity. I couldn't understand the appeal of beautiful but dim, and honestly still don't, though now I get what Piers Anthony appeared to think was the barbed satirical point of what I will for lack of a better term call his "jokes.")
I say go with Terry Pratchett's "Truckers" series and, if you must have puns, then "The Phantom Tollbooth." Also Lloyd Alexander is generally okay, and the Bunnicula series is always tops.