I've added Poweramp to the power saving exclusions and it is now working as intended. Thanks!
I have both "Resume On Wired Headset" and "Resume On Bluetooth" turned on. Pause and Resume works with bluetooth disconnect and connect, but after a bluetooth use when the player is paused, if I connect a wired headphones, it does not auto-resume. If I press play, it works correctly, and from this point, If I disconnect the headphones, the player pauses, and resumes on connection again. I have a Sony Xperia XZ1 Compact and I use a jack-USB-C adapter for my jack headphones.