I just gave it a try on my Windows 10 computer, and my buttons are correctly showing the down state.
I recall that Starling used to have a bug on Windows computers with touchscreens a while back. If you're not on the latest Starling, you should try updating.
If you're on the latest version, or updating doesn't help, have you tried running your app with the debugger on Windows? It's always worth trying when something seems broken on only one platform. Often, there's a runtime error that the debugger can catch. I remember when I first started working on Feathers that I'd frequently have everything working well on either iOS or Android, but then I'd try it on the other one, and things would be broken because I didn't handle some edge case that didn't affect the first platform.