When using the Folder resource in a course that has been set up to show all the topics on a page, when setting the Folder resource to "Make available but doesn't show on the course home page," the availability editing settings are not present from the course home page. 

Steps to reproduce

Enable stealth mode

Advanced features / allowstealth => yes

Create a Folder activity (key settings below)

• Display folder contents: Inline on a course page
• Availability: Make available but don't show on course page

With Editing Turned on, from the Edit Medu from the course home page select "Make unavailable"

After selecting Make unavailable for the Folder activity, click the editing menu, and you will not see the "Make Available" action from the drop-down menu. 

Note this does not seem to be impacting other activity types, just the Folder Resource. In fact, it's working properly when the folder contents are displayed "On a separate page"

E.g. below of the URL resource with the "Make Available" displayed.