Checked some (older) AT&T sales reviews of the phone(s) and it seems they have some issues as:
1 - dropping calls
2 - caller can't be hears (noise cancellation?)
3 - big buttons activated by accident
Point 3 is ridiculous IMHO, as a simple application logic could resolve this: gesture alike.
Point 2, if noise cancellation, this is just a user issue
Point 1 including 'reboot' is surely not fun.
Have to see how market perception and phone seller pick up the 'fixes'.
Can they continue on their recovery into cash flow positive next year?
If so - great price, otherwise a complete failure possible.
And that is probably why stock dived this low.
In comparison, $TNAV has a much more overvalued price now than $SONM
and their customers are about to potentially jump ship, not just GM.
Ford (F) may also want to downsize their cost factors.
Telecom hardware retail biz sector is not easy for SONM.
Hence the interest: Finding the bottom.