There have been many reports of the Aeros losing the recorded tracks.
I noticed that at least on one of my 2x2 tracks, the issue was that I recorded the first part, but upon reloading, the the part was actually in part two. Since the 2x2 mode shows part 1 by default, it looks empty.
This was in a free-form track if that matters.
I suspect there’s some issue where part one and two get mixed up; it’s possible that I recorded on part two initially (but unlikely). This has happened to me too many times for this to be explained by operator error (but I’m not sure)