hi, I've always had my .bak and .sv$ placed in the same folder together like this guy in this video  (autosave folder), 

https://youtu.be/OFkgutw0w3c?t=16

and suddenly last week autocad started to put the .bak files in the same location as the original draw. people says it's autocad normal behaviour but I have spoken with few collaborators (macOS users) and they all have the .bak files in their autosave folder, so I'm pretty confused and I don't like to have .bak files everywhere.

your screenshot looks exactly like mine and yes I tried to change the location with no results.