Audio resumes, then pauses, then resumes again... why?

[griff]

I have noticed a strange occurrence with audio playback... but only when in my car. This is somewhat related to an issue I have had with the LG Hi-Fi Plus, but I am not sure on the exact cause. 

I'm using an LG G5 (H860), not rooted, build no. MMB29M, software version V10h-TWN-XX. I'm using Poweramp to play the music. Poweramp version 2.0.10-build-588-play. 

Poweramp has this nice option to auto resume music playback upon headphones or AUX being plugged in. Works the same when you unplug (pauses music). I have both those options enabled, so when I get in my car I plug my phone into the AUX cable and music plays immediately.

HOWEVER, I've started noticing that a second or two (sometimes a lil longer - 5 to 10 seconds) the music will temporarily pause, then after another second or so it resumes again. This doesn't happen every time, but I would say frequently. I don't recall if this was happening with my last couple phones (Samsung Galaxy Note 2, then LG G3). I've had this G5 for about 2 or 3 weeks now. I mentioned the LG Hi-Fi Plus above because I bought that with the G5, but in my car the music was randomly stopping, but not resuming like I described above. I've since sent the Hi-Fi Plus back. I've tried various different music files (ones ripped from my CDs, ones bought from Google Play Music and ones bought from Bandcamp). I've tried using three different cables. I have the Audio Buffer on highest setting (+750ms) and Audio Thread Priority is on Highest. I have two Bluetooth connections going, one to my Pebble and one to the car. I've troubleshot this by killing both, and the issue still occurs. 

I've captured this issue happening in three video files, all uploaded to my Dropbox here: https://www.dropbox.com/sh/uffrjrxzjpfdegc/AABp1iPVJh6fS4SHqkHQ-8lMa?dl=0

The first video file isn't the best example because the first track has a spoken intro, and the pause occurs during that. 

Has anyone heard of anything like this? It might be a Poweramp issue, but I cannot troubleshoot that because I don't know of any other music apps that have the auto resume feature. I will do some research... Alternatively it could be the G5, or even the car. Maybe I need a Ground Loop Noise Isolator.