When I moved to Murena FP4 MS Teams worked fine. Only after a while the “Mickey Mouse” problem started. It coincided with my company deciding to increase security through Company Portal app, so I thought this was the cause. I tried installing the Company Portal app, but without success. In the end I found a workaround:
Ever since, my MS Teams works normally when I use my Bluetooth headset.
I still have the problem when I use the phone speaker, but I gave up trying to fix it since it’s more convenient to have the calls with the headset anyway. 