Quote Originally Posted by skipwater View Post
In your admin Configuration->GZip Compression check that it is set to 0 = off.
Skip, it took me a while to understand that I first had to activate this menu option in admin permissions...

Anyway, no, it was not active, and has never been in the past...

In the meanwhile I'm trying to make some small backwards steps, to double check what made Backup ZC stop behaving correctly...