I am a fan of (JRiver &) JRemote, but are running into 2 issues:
1. Regardless of which track of an album I choose, JRemote (version 3.29; iOS 13.1.2) plays the first track of a multi-track Flac-file (+cue-file).
More severely, but not unexpectedly, a similar error occurs when shuffle-playing a genre or other groups of albums. When playing an album, track two is played after one, et cetera. JRiver (25) does not have any issues (in this regard).
I switched my large Alac-library to multi-track Flac, because of the (still) unresolved issue that JRemote cannot find / play many tracks/albums, which JRiver finds and plays. JRemote now finds every album. So switching to individual tracks is NOT an option.
2. JRemote does not play any video. The screen remains black.