When there are already some content items selected into the content sharing policy, then opening ALL CONTENT may remove some items from the list.
Clicking CANCEL without making changes will nonetheless leave a different list of content
Aria Automation 8.16.0
Aria Automation Service Broker 8.16.0
This is a known issue in Aria Automation 8.16.0
The fix is found in Aria Automation 8.16.1 or later.