Apps report the phone's using mobile data even though it's connected to a WIFI
The problem is really troublesome. I was trying to solve it all night. I did a full wipe &amp; fresh flash but it didn't help. I dirty-flashed old builds including cm-13.0-20160730-NIGHTLY-bacon and cm-13.0-20160802-NIGHTLY-bacon, the problem remained. Then I restored a 6/6 twrp backup, problem solved! I dirty-flashed the latest nightly onto the restored backup, everything worked like a charm. It's beyond my knowledge to tell what went wrong but anyhow it's solved and hopefully it won't happen again.