More a FYI for anyone who has a problem.
I started my Sprint Hotspot on my phone and it would go active for a second or two, then shut off. No messages, nothing helpful. I tried for a half hour with no luck. Gave up and shut down my laptop.
But then I went to Settings->About phone intending to check my signal strength and happened to notice my up time was 321 hours. Well... .this isn't Windows but ...
Restarted my phone and Sprint Hotspot started fine. I didn't actually have any time left to actually boot my laptop and use it, but it stayed active and showed an active notification on my phone.
Was hoping Android wasn't another "when in doubt, reboot" but maybe I was too optimistic.