Question [HELP] Loud humming/buzzing when calling with MTW3 earbuds on Xiaomi 11T

[FortieSicks]

Hi everyone,

I’m having trouble calling with my MTW3 (Momentum True Wireless 3) earbuds when connected to my Xiaomi 11T (MIUI Global 14.0.4). When my MTW3 (Sennheiser Momentum True Wireless 3) is connected to my Xiaomi 11T and I want to call I get a really loud humming/static/buzzing sound. This starts with pressing to call (right after pressing the green telephone button), the other person doesn’t need to answer the call for the problem to occur. When the other person accepts the call I can’t hear them, they can’t hear me. When I enter a call in Discord the same happens.

I tried connecting the headset to my girlfriends phone (iPhone) and the problem does not occur. I also tried connecting a different (QCY-T5 Pro) headset to my phone and the problem does not occur. The problem seems to be the way the Xiaomi 11T and the MTW3 connect to eachother. A replacement pair of MTW3's and a phone factory reset did not solve the issue.

Thank you for your time and help in advance!


What I tried:

• Reinstalling the Sennheiser app
• Calling with Sennheiser app installed
• Calling without Sennheiser app installed
• Factory resetting the Sennheiser app
• Factory resetting the MTW3 earbuds
• ‘Reset wifi, mobile network and Bluetooth’-option on Xiaomi 11T
• Factory reset the phone
• Tried a replacement pair of MTW3

What does work:

• Connecting the MTW3 to my Xiaomi 11T
• Listening to music (Spotify/Youtube)
• Sending a voice message on Whatsapp
• Calling with a different bluetooth headset (QCY-T5 Pro) on the Xiaomi 11T
• Calling with the MTW3 on a different phone (iPhone 11)

What does not work:

• Calling (normal phonecall) with the MTW3 on the Xiaomi 11T
• Calling (in Discord) with the MTW3 on the Xiaomi 11T

Bluetooth settings:



Developer options when connected to MTW 3:



Sennheiser app settings: