Yesterday I wanted to try somethig with the display lock. My lock is “wipe” and I did set this to “pattern” with “on/off locks device” and pressed the power-button. Waited 10 secs, pressed power, wiped from bottom to top and homescreen was there without the need to paint the pattern.
The same with password, PIN and/or time to lock set to zero, waiting until the automatic lock set in. No success.
Only after rebooting I had once to give the pattern/password/PIN once.
I can’t reproduce this on Open OS. I have to paint the pattern every time “power button instantly locks” or “automatically lock xx sec after sleep”.
I’m guessing an app bypasses the pattern unlock (device manager?, root?).
The only apps of question are Gravity Box and XPrivacy. In XPrivacy I could not find anything concerning the problem and Gravity Box I tried some changes “background” and “smart start” without change. Hmmm, no clue where and what …
Update: I tested my phone in failsave-mode: the behaviour was the same. So IMHO no app involved.
Did you maybe enable “Smart Lock” in Settings/Security? With this function you can choose for example “safe” places (home, work…) or bluetooth devices (car audio, finess tracker). When your phone is in such a “safe” zone, it doesn’t need to be unlocked.