Ok, so you've made a mess with your configuration changes. This is probably a basic problem, though.
Use a desktop web browser. Press Ctrl-Shift-P if you're using Firefox, or press Ctrl-Shift-N if you're using Chrome or Safari, to open a "private" or "incognito" browsing window. In that window, sign into the one, and only one Google/Gmail account that holds your Google Voice number, and go here:
https://voice.google.com/settings. Do you see your inbound Google Voice number at the top of the page? If not, this is the wrong Google account. Close the browser, open it again, and open a new private/incognito window, and repeat, until you find your Google Voice number. You cannot proceed without doing this first. Once you find it, press Ctrl-T on that private/incognito window to open a new browser tab. On that tab, sign into your OBiTALK dashboard:
http://www.obitalk.com/obinet/pg/obhdev.
Completelyl delete both OBi devices off of the OBiTALK dashboard. Wait a few minutes for the system to remotely reset their configurations. Pick up the phone on each OBi device, key in ***8, then 1 to restore the device to factory defaults. Add one of the devices back to the dashboard. After the device is successfully added, go through the Google Voice setup. When presented with the pop-up screen to confirm you're using the correct Google/Gmail address, make darn sure it shows the same address that holds your GV number. Finish the procedure and it should work properly.
Repeat this with the other OBi device. Do NOT make any expert mode changes.