According to an Apple Insider post, it seems that the iOS 7.1 update brought unexpected problems to users, who suddenly have 'Personal Hotspot' issues. iPhone owners who use the Personal Hotspot feature on cellular networks that do not support it are out of luck. After the iOS 7.1 update, the ability to manually edit tethering settings for unauthorized carriers have been disabled.

Unhappy users turned to Apple's support forums to gripe about the issue in a thread that has exploded to almost 16,000 views, and more than 200 individual replies. Users from U.K., U.S., Netherlands, Italy, Sweden and Estonia have aired their problems, saying their tethering ability was deactivated after upgrading to the latest version of the mobile operating system.

Access Point Name (APN) settings for Personal Hotspot are not saved when the user backs out of the iPhone Settings app, reports said. The problem has been spotted in every OS that is compatible to iOS 7, including iPhone 5s.

Carrier authorization - or lack thereof - seems to be the issue, after testing results as well as conversations between Apple support agents and forum users. Users whose carriers support Personal Hotspot reported a smooth experience. Those who experienced the issue and swapped SIM cards with an authorized carrier appeared to have a smooth experience as well.

Some reports suggest Apple blocked personal hotspots for carriers which do not allow the feature. However, others posted disapproval to this assumption.

Another group of users to be affected by this issue are those whose carrier allows tethering, but has no partner agreement with Apple. It appears that most have been abusing the enable Personal Hotspot function without fees.

Tethering without authorization has been a cause of friction between iPhone users and wireless service providers ever since. After the deal between Apple and AT&T secured unlimited flat-rate data plans for first-generation iPhone buyers, the carrier has been in a battle with users who are tethering apps without authorization, until officially supporting the feature after three years.