If the original request is a Range request then subrequest doesn't use Range header.
So if a zip contains for example 2x 10G files and Range request was made for the last 1G of the second file then mod will subrequest the whole file and just skip the first 9G of the file.
For a client it looks like a download is not started for 2-3 mins. And since most downloadmanagers have just 60 secs timeout it will fail on such files.
Test environment (nginx.conf and other files):
These posts from another users seems to be related to the problem:
Any updates for this issue?