Hi Bhargav,

AQM only applies to Standard Agents which operates on Queue classes(tables). 

For agents of the Standard queue mode, indicates whether the agent uses the agent queue functionality. When this option is selected, the system locks items that are retrieved from the queue by the agent until the agent is finished with the item (commit or rollback). If a transient condition means the item can't be processed (perhaps the work item is locked), the system requeues the item and the agent can try again the next time it wakes up.

When this option cleared, the queue items for this agent do not persist. That is, when an agent attempts to process an item, that item is removed from the queue and the agent gets one chance to process it. If it fails, the item is not put back in the queue for another attempt.

I am unsure which version are you on. We must see another set of options like below when we select Advanced agent.

AQM checkbox only shows up Standard agent option in Agents rule form. Have checked from 7.2.2-8.4 versions.

Even if it showed up in older versions, it won't add any value to advanced agents.