Try the PBS Kids app. The shows are consistently cast with good role-model children and adults, without being preachy. Many episodes show how to resolve mistakes, frustration, and conflict in beneficial ways.

In comparison, the behavior in the kids shows from other producers (Disney, Nickelodeon, etc.) sometimes presents nasty behavior and name-calling as either inevitable, or something that's "someone else's problem": the instigator, if they're punished at all, might suffer the wrath of an authority figure, or simply bad karma.

My intent when choosing shows is not to hide the existence of bad behavior from children, but to teach them how to deal with it.

(My children also read Calvin and Hobbes. And watch those less-wholesome shows. And binge-watch MrBeast when I'm not around...)