If you're having trouble with the Microsoft Teams app on your mobile phone, try the following:
- In your Teams app on your mobile device, sign out of any Teams accounts.
- Uninstall the Teams mobile app.
- Reinstall the Teams mobile app.
- Sign back into the Teams mobile app.
- Enable the prompts for allow notifications and allow access to the mic
- Open the Teams app and tap the phone icon, you should get a prompt whether to allow access to your contacts. You must accept this, otherwise you need to repeat the above steps again, particularly if you are experiencing any call issues.