Firefox on linux suspending network activity upon locking screen / switching users
Firefox (and thunderbird, as well) seems to be suspending network activity when doing a vt-switch or user-switching or locking the screen. The effect of this is that ongoing downloads freeze and are resumed (sometimes fail) only after unlocking the screen.
Chromium, wget, etc., on the other hand appear unaffected and the download progresses during screen lock / vt-switch.
I do not remember when exactly this problem started, but could have been since a couple of years.
This problem also occurs when running the latest firefox (downloaded tarball from mozilla site) and a blank profile. So it could be some interaction between firefox and the window manager / xsession.
My setup is a desktop computer connected via ethernet cable running XFCE on Debian.
How do I go about diagnosing / fixing the issue?
Thank you. Raj Kiran