People I called could not hear me (one way audio). We had recently changed phones (to a VTECH) and everything was okay. Then all of a sudden we started experiencing one way audio. I spent hours and hours on the phone with OOMA support. Finally, it was fixed by:
Unplugging the VTECH phone base, waiting 20 seconds.
Plugging the phone base back in.
Unplugging the OOMA box, waiting 20 seconds.
Plugging the OOMA box back in.
Once the box rebooted, problem was solved.
May not fix your problem but I hadn’t seen this described anywhere else.
Good luck!