The problem is with both wav and flac files.
"re-ripping" I have the music in both original published CD and downloaded formats. I tried using the downloaded wavs first of course when the problem showed up. So then I extracted the CD tracks via Goldwave to wav files, but the problem still existed. I've extracted many CDs that way and they've all played fine my phone.
I'm stubborn, so then I recorded a track from my CD player via the input jack on my computer's sound card. Too weird, because the problem STILL existed!
"lower level of bit rate." No, I haven't tried that, but I will once I figure out how.
"Poweramp" The same problem happens with Samsung's ubiquitous music player, but I'll try that too thanks!