I've had this issue on my older Android phone. For me I noticed the issue when the Cellphone dropped GPS or switched cell towers. After some research this was an issue for some Android devices. For me it was mostly Spotify that was causing the distortion. Running audio apps like Audible didn't seem to be an issue.
These issues happened with all Bluetooth audio devices. Mine eventually went away after Spotify updated a few times. Have you tried other using other Bluetooth Audio Devices? Make sure all of your audio apps are up to date.
I would contact @AnkerSupport at email@example.com or try their chat service on the Soundcore Website. Make sure to give the steps you have already tried, serial number, order number, and date of purchase. These steps will help speed the support process.