Additional features, settings, or issues not covered by specific Microsoft Teams Free categories
I Faced same issue while I logged in Same account with Different devices like Laptop, Android and iOS device.
I Checked many things here and lastly I try my self and issue resolved .
I checked Notification setting of my account in Teams app on click on Home burger button click.
Bottom of screen there is a option Block Notification -> I Disable a Option When Active on other Devices and then I am able to get notification on all devices.