Mobile users unable to receive invite to worlds, but can send invites

When a mobile user is sent an invite to a local world over Xbox Live, it is never received.
Sending an invite from their own local worlds (to non-affected platforms) works as expected.

Affects all ISPs. Needs confirmation if iOS devices are also affected.

Tested devices:

Samsung Galaxy Note 4 (custom ROM; 5.1.1)

Lenovo Moto E⁴ (7.1.1)