I looked through the sort results once again, but I can't see any pattern. There is a small difference from test version 1.3.0.3, now getting this sequence:
27/3, 20/3, 18/3, 17/3, ..., 15/3, 14/3, 12/3, 8/3, 7/3, 28/2, 1/3, 2/3, 3/3, ..., 7/3,
Compared with 1.3.0.3 some dates moved from the trailing end to the top, but still there is this strange sequence with descending dates down to 28/2, then changing to ascending dates. This is particularly strange since your normal sorting is correct. It has nothing to do with change of month, because I have a new track from 4/4, and that one is listed at the correct place.