May be these are the reasons.
The current sheets are Un-Approved.
In Qlik Sense, users (with permissions) can create their own sheets. These sheets will not be seen by any other users unless the owner chooses to publish them. Once published, the sheet goes into the Community sheets area.
If, there is QMC Utilities.
The Sheet Approver enables users to approve published sheets in an app, thus, making them base sheets of the Qlik Sense application. In addition, it's possible to un-approve sheets as well and push them back to the community.