Consider checking whether your Tailwind configuration conforms to the restrictions for max-* variants to work. Otherwise, consider providing a reproducible example please.

Tailwind Version Compatibility

Custom screen sizes like max-[600px] and arbitrary values were introduced in Tailwind CSS v3.2+. Check your version:

bash
npm list tailwindcss
If you're on an older version, update:

bash
npm install tailwindcss@latest