Has anyone seen this behavior?
In a subsite I create a new document library (the problem will also happen with an old DL).
I ensure that Display in Quick Launch bar has Yes selected.
Click Ok, return to site's Home page.
-->The new DL is displayed in the Quick Launch Bar.
Refresh the page, or navigate away from the site and return
-->The new DL is NOT displayed in the Quick Launch Bar
It gets worse. If I return to that DL's Modify settings and Change General Settings I can select Display in QLB=No, click OK, again Change General Settings, select Display in QLB = Yes....
Now again the DL will appear in the QLB for exactly one page load. Refresh and it's gone....
Ack!