I'm wondering if SeeYou is confused by the fact that the flight wraps
around midnight (UTC) and apparently starts after it has ended.

When I run animation against the relevant IGC file its starts at the
launch time but when it reached midnight UTC (part way along the second
leg) it thinks the flight has ended and jumps back to the launch.

Looks like this could be a SeeYou bug - even if it's not the root cause
of the original landout problem.