Verify in app purchases are enabled if restore all function is not working. 

How to enable:

1. Go to “Settings” then “Restrictions”

2. Check that in app purchases are enabled. If not, enable them and repeat the restore all procedure.

Steps to Access:

1. Verify you're on the same iTunes account you used to purchase subscription. 

2. Click "Library" button in the menu bar.

3. Click "Missing Issues" - top left side

4. Select "Restore" - now re-download issues.