IH006 Sound issues

We just got our second IH006 for our second child. The sound is awful! Even on max volume (and high in the menu options) the sound barely registers. It also cuts in and out and goes silent. Video is choppy too. Our other monitor works great and did not have any of these issues which is why we bought a second. I’ve reset it to factory settings 5 times. Deleted the camera and re-paired. Any ideas?!!