Tested on both DJI Go 3.x and DJI Go 4 on Android (Samsung Note 4) with everything running latest versions, firmware, etc etc.
To reproduce hold down the C2 button and adjust the right wheel. The gimble roll (horizon) should change but it does now. I have verified the button hold setting is indeed set to gimble control and now focus and that setting makes no difference.  DJI staff and other customers have mentioned this feature but it seems to no longer work.

Could someone pass this onto the developers as a bug report?  Others have reported this problem in the following threads:
http://forum.dji.com/forum.php?m ... mp;extra=#pid587054
http://forum.dji.com/forum.php?m ... mp;extra=#pid587321

Thanks!

Unfortunately, we may be stuck without that. There was a bug that adjusting the gimbal also adjusted the exposure at the same time. Their way of fixing it may have been removing the gimbal shortcut feature entirely.

It's possible that there's a hardware issue, and the remote just isn't wired to use the right wheel without changing the exposure. If that's the case, then there's nothing they can do until they change the hardware. If it's just a software problem, then the programmers may not have understood the problem when people reported the bug. They may have thought we didn't like the gimbal control shortcut, when actually we just wanted it to stop changing the exposure. So that would mean that it's fixable in a firmware update, but they'd have to clear up the confusion to understand the problem.

This is all guesswork. I hope they can resolve it, but I can't say for sure if it's possible or if this is a hardware issue.