This is really odd, and quite frankly I can't understand how it is happening. I'm syncing to two Android-based devices - a Samsung Galaxy S8 and a FiiO X5-iii. I'm using the same player on both (GoneMad Music Player although this should matter.)
The playlists sync to the FiiO just fine, but not to the Samsung. Both use M3U playlists. After the sync, looking at the Playlists directory with a file manager, the FiiO has all the M3U playlists. The Samsung not only has the M3U playlists, but also PLA playlists, which contain zero bytes. The M3U playlists are missing the first letter of each line, making them unplayable. I'm trying to sync two playlists to the Samsung and I'm only getting one of the M3Us (containing data minus the first letter.) And I get both of the PLAs, which are a)empty, and b)not set up to sync.
The MB's device settings for playlist are both the same with one exception: The FiiO has a field for "path prefix for tracks" while the Samsung doesn't offer that field. Both devices have a Playlists directory and both have a Music directory. Neither use relative file paths.
@frankz- did you actually play any playlists on your Samsung since you did the sync yesterday? If not, please do so. And look to see if the first letter is missing from each line in the M3U.