Apple has posted a new support article regarding Wi-Fi Assist, a feature that first appeared with iOS 9. The article details how Wi-Fi Assist is supposed to work and how to turn it off.
From Apple:
Wi-Fi Assist automatically switches to using your cellular data connection if you're experiencing a week Wi-Fi signal, and some users have complained that because of this feature, their cellular data allotments are being used up rapidly.
Wi-Fi Assist automatically switches to using your cellular data connection if you're experiencing a week Wi-Fi signal, and some users have complained that because of this feature, their cellular data allotments are being used up rapidly.
Apple also offers some additional information on Wi-Fi Assist. For instance, the feature only works when apps are in the foreground, and does not support background downloading, nor does it activate when you're data roaming.
Check out the full support article at the link below.
Source: Apple
