EP-T21 earbuds and MacBook Pro

I have pair my new EP-T21 with my MacBook Pro Retina mid 2014 today (MacOS 10.15) and MacBook recognizes them but i have an issue: when i use earbuds in videoconference platform they work bad.

I have used them with Skype and Cisco Webex and i have the same problem: I hear jerky voices and other people hear me bad.

I found that the problem happens when both the microphone input and the sound output are set to earbuds; when i set another microphone input (for example the integrated mic or the mic of the webcam) there are no problems.