I just installed an Android 7.1.1 Nougat update on a Galaxy J5 (2016) phone in our family. (It's running Samsung Experience 8.5, if that's relevant.) There's an annoying problem with Bluetooth stereo headphones that previously worked flawlessly with many phones, including this one. The problem is that Play/Pause button stops the playback (as it should), but another press doesn't resume it. I've tried rebooting the device, unpairing, switching bluetooth on and off, and nothing helps. Could someone help on this?
A lot of this depends on:
1. How good the music app you are using is programmed.
KeyEvents your Bluetooth headset sends and how your app handles them.
I guess your headset uses same button for play/pause so there might not be proper handling of
KeyEvents on the app side.
The solution is to try different app for music playback, check if YouTube app is working OK with your headset.
I will suggest you to use Google Play Music, as it works great with my Bluetooth headset with single play/pause button, running on Moto G4 Play (Android version 7.1.1).