Accidentally had LB Android and PanoScrobbler both submit listens at the same time, but noticed that the submitted listened_at times between these two differred by several minutes. in fact, the times didn't really differ, but the tracks these times were associated with: LB android was submitting the tracks using the listened_at timestamps that PanoScrobbler had used for the previous track.

see e.g. here: PanoScrobbloer submitted "Cheerleader" at 12:39 in my timezone but LB Android submitted the same song at 12:42.
This is exactly the timestamp that PanoScrobbler submitted for the next song, "Break Your Heart".

Testing out which timestamp is actually correct i discovered that PanoScrobbler is right and LB is somehow lacking behind one track.

This was observed on the current version 2.4.0.

Screenshot of the mentioned example: