Samsung Mobile's Arabia official Twitter account while acknowledging the issue when replying to a user also confirmed that the team is working to fix the issue. While the fix might be not available to users currently, Samsung suggested owners of the Galaxy S6 and Galaxy S6 Edge to format the phone to get back the features. The bug is causing various toggles on the Quick Settings panel to disappear and annoyingly there is no way to bring them back.
Samsung Galaxy S6 and Galaxy S6 Edge users are reporting about the issue on various sites including XDA Developer forum. One of the threads titled "Missing Toggle in Quick Setting Panel" include complaints from several users.
One of the users posted, "Today I switch on mobile data using the toggle in notification area and the turn off after some usage. Later on, I tried to turn on again and the toggle disappeared? How do I make it show up again? No software update was done. Phone is completely stock. Never rooted it."
Another user claimed to face the same problem on his Galaxy S6 Edge and noted, "Same problem with me: Missing Mobile data toggle Galaxy S6 Edge."
One of the XDA Developer forum members named NimeniAltu has claimed an unofficial fix for the issue that brings back the mobile data toggle on the handset. However, we would warn users to try this at their own risk - the apk files being provided have not been verified.
Recently, Samsung started pushing Android 5.1.1 Lollipop update to Galaxy S6 and Galaxy S6 that is likely to bring several bug fixes for the devices.