Long time user of the Slim / Slim+.
I got the Spirit and I noticed the audio seems to fade up / down a lot. In recorded videos (MP4, Netflix, etc) it seems to ramp up over a couple of seconds, which is not bad. But in Youtube it ramps up/down often, every few seconds.
My phone OnePlus6 works badly with these, an old tablet (Nexus 10) works better, so I'm thinking its a device / version issue, i.e. Anker Soundcore software.
Dud unit, "feature" or a setting I can alter?
Warranty / support is not a concern, I know I can get a replacement, it is just if a replacement behaves the same, I wasted time.