Diagnostics does not see my iPod Classic so I can sync it to iTunes?

Try iOS device not showing in iTunes for Windows - Apple Community.

tt2

The iPod Classic isn't an iOS device - surely you know that...? 🤨 I'm even more surprised that Apple recommended your reply (makes me wonder if they're not being 'recommended' by a bot). The Classic was the predecessor to the Touch. It's likely that, considering that the Classic (1st generation) was released in 2007 and the 2nd in 2008, that it's demised.

Apologies, I meant to include the addenda that the same steps (explicitly reselecting the device driver) can help with iPod classic too.

tt2