Yes, the "up" button on the volume rocker no longer functions/operates. Hoping it was a software issue, I tried wipes, different flashes, stock, taken OTAs, etc. But to no avail...*sigh*
It seems I have no choice but to return it to Sammy. I'm very reluctant to do so as I'm worried they will find some evidence of root...in which case I'm assuming I would need to pay to get it back. And that cost would likely exceed what I'd be willing to pay.