EP-T21 No Audio output right ear

Purchased EP-T21 from Amazon a few days ago. Out of the box, the device worked perfectly and connected to both my MacBook Air and iPhone. Last night, the audio output of the right ears stopped. It is not muffled or clogged, it is gone. The device is still paired since I can use the “next song” feature with the touch sensitive area. The device is charging and read fully charged. I tried all the troubleshooting suggestions in the user manual but none have so far worked.

Thanks,
David

Hello! I have a similar problem also with the EP-T21: the right earbud disconnects (short beep and then no audio) itself many times after a few seconds of use.
Any solution?