For me, this isn’t really a serious problem. I used to have headphones that didn’t have any controls at all, and that worked fine. But it’s still strange.
chiming in with my 2 cents. I was running OSK 1.2.0 for a pretty extended period of time, even waiting through the launch of 1.3.0 to install 1.4.0. I have a pair of headphones, V-Moda Crossfade M100’s that I have had for probably a decade. No issues noted on 1.2.0, running local audio through Auxio application to line-in headphones. I now experience issues on OSK 1.4.0 with what appears to be reduced audio quality. I am able to fix this bug by force stopping Auxio and then turning on Mono Audio under Settings->Accessibility->Mono Audio, then toggling it back off and launching Auxio. This may be just a bug present in OSK 1.4.0 or Auxio itself, but it was not present in my entire time owning the device from the time of 1.1.0->1.2.0 release timelines, and I had a pretty good habit of switching to offline+ for music consumption after work with no issues like this on 1.2.0.
Edit: I also notice a significant increase in volume to the headphones after this too. It almost seems like it’s only playing one channel of audio initially. Wonder what would have change from 1.2.0->1.4.0 that would affect this. One notable item I can think of was introducing stereo speaker playback utilizing the earpice of the device as well as the bottom speakers for playback. I am not aware if this was present in 1.3.0 as I did not run this OSK version.
Further Edit:
I was listening to a podcast on AntennaPod and was in online mode, and I noticed that if I switch to offline+ mode, this removes my ability to use the line-in controls for play/pause/skip. When I went back to online mode, I was once again able to make use of line-in controls.
I can confirm problems with Offline+. When this is active, the sound is very quiet and thin. When I turn Offline+ off, the sound is louder and stronger again, as it should be. And the pause/play buttons on the headphones don’t work when Offline+ is active.