We've discovered that the CCX400 and 600 has a stuttering bug. On a random moment the speaker or headset starts to turn green and white very quickly en you hear the speaker or horn starts to stutter the tone. The only temporary fix for this is to restart the phone.
We manage the phones using the teams portal.
Hello @KoenSupport ,
Welcome to the Poly Community.
The software you are running is not a GA software so this tenant maybe some part in the Microsoft TAP.
Microsoft and Poly are aware of this issue and Microsoft is adding a fix for this into the Teams IP Phone Android app.
The issue is tracked by Microsoft and the only workaround, for now, is to Downgrade at least the CCX500 to the original 220.127.116.112
Within Poly we are tracking this as EN-180835
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.