The always available offline option is there. But it does not do anything and that is my problem.
Share1 is containing "My documents" and I was able to make that available offline. The Share2 is containing "Download". When mapped to the second share using the same username/password used to connect to Share1 I have the availability to enable offline files, but as said... that is not doing anything.
The second link is not really telling me what I might be doing wrong. Sorry