tailwind classes not having any effect

[MortenHofft]

I have difficulties getting tailwind classes to be used. What am I missing please? According to the documentation there are utlitiy classes to set the max width https://tailwindcss.com/docs/max-width
e.g. max-w-9 - but it does nothing for me.

<div className="max-w-9 bg-slate-200">I would expect this to set a max width, but that isn't so https://tailwindcss.com/docs/max-width</div>

[MortenHofft]

Turns out that we were using 3.3.5 and the documentation is 3.4.0 and I was using classes that had been added in October
tailwindlabs/tailwindcss#12300

I've updated the dependency