Files are two about 6,5 GB zips (no extension) downloaded from /root/subfolder
Sorry I can’t give the files for testing, they are private backups. I’m sure a random file works for testing.
I have downloaded them with Webmin daily for a very long time without problems (apart from an odd speed limiting/slowing that happens just before 1GB is done, that may be caused by Java).
I did not notice other issues, but then again I use Webmin for monitoring mostly. The odd issue was instant Swap 100%, did not effect anything adversely but after I reinstalled the old Webmin I cleared it out without problems.
With 2.102 the download process started slowly, it opened the tab and slowly after 10 seconds Chrome got it into download page (filename and size were correct) where it said after a moment it failed due “network error”. My network was fine, Webmin refreshed normally (1 gig fibre at home).