The screenshot seems to be from the traffic log, it also states the "control action" "detected" under the app control, which means it is detected but not blocked. It should say "drop session" in case of app control block.
The action part in the traffic log refers to all UTM profiles, so it might be blocked by another UTM profile, not by app control. Check the "application control" logs to see if it is really blocked by app control. Check the other UTM profiles like webfilter or IPS if any are applied to check for blocks there.
If it is confirmed it is blocked by the application control sensor, try to drag and move the pinterest allow fillter on top, so it will be with highest priority and have a test.
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.