Thank you all for help!
I sent ring for warranty on April 29, 2014, nothing yet.

Signature -> V1ntage

@Lafunamor said:

You can choose between buying a replacement ring for half the price or send your broken ring in and they send you a replacment

Any idea how long it takes to get replacement?

@Lokki said:

@vokmed did you contact support@nfcring.com and let them know there's a defect with your ring?

Yes I did. I decided to send back for warranty exchange, if one side has a problem the other might develop too.

Thank you guys for help

I just got it today and it only been 3 hours old.
Registered, setup unlock tried few times and got myself locked out of the phone, could be custom wallpaper which I removed after cold reboot and email sign on.
But, my classic ring, one side (white?) right of the box DOES NOT work, just the black side (public?) .
I am confused, classic, which side is private and which is public???