I do tend to go after a "grouped" file
as the odds of finding one of them with an available download slot are much better,
However, the problem also occurrs with a single download host request (download all).

My recollections are, that (with ANY- LW 2.x.x)
when the incomplete (resuming) download appearrs in the LW download window after a restart,
the host address is the same as the original attempt, and,
although I do nothing,
the incomplete download appears in the download window
and resumes at 0% regardless of the % I reached in the previous session.

This problem does not happen in my LW 1.7,
LW 1.7 usually completes incomplete downloads as long as the original host is (still) available.