Apple has had a few busy weeks. The Cupertino-headquartered tech company recently released the iOS 9 for its numerous devices weeks ago and followed it up with several updates a few days ago. The newest operating system is said to be the fastest rollout in the history of the company, with the iOS 9 now running on more than 50% of its devices.

However, CNN Money reports that as expected, some bugs were discovered that Apple quickly addressed. But while the company's iOS 9.0.1 update was able to head off an issue where customers lose their cellular date due to a customized APN setup, another setting is said to be causing more problems. However, unlike the previous problem, this one isn't a bug, but a default setting in one of the new features available in the iOS 9.

The feature in question is the iOS 9's "Wi-Fi Assist," which makes it possible for an iPhone to automatically use 4G cellular data in order to boost a weak Wi-Fi signal. It's admittedly a very helpful feature as it eliminates those situations when you can't send a message or your live streaming is suddenly cut-off. With "Wi-Fi Assist," the device is automatically shifted to the cellular data plan when one is on a weak Wi-Fi network.

Meanwhile CBC reports that although it is convenient and will do away with annoying buffering issues, it might not be such a welcome feature for those with a data cap as it might lead to additional data charges. Numerous users have been shocked with these extra charges and have taken to Twitter to report the experience. Some have reported data usage that rose from the regular 1 GB per month to 3 GB, and even to a shocking 7 GB. What's even worrying is that the "Wi-Fi Assist" is a default feature that's automatically turned on when one updates to the iOS 9.

Luckily, iPhone users don't have to wait for another update to roll-out as it's easy to fix. Users should just go to Settings, choose Cellular then scroll down to "Wi-FI Assist" and turn it off.

Apple is said to be aware of this issue but hasn't made any comments yet. However, going to settings and turning off the feature is the easiest and most viable solution to this problem at the moment.