A configuration rule has been defined to exclude some disk drives from being monitored. But the drives get re-added back for monitoring.
The configuration rule, when run manually, will execute as per the rule action configured. But during data collection, the configuration rule will run based on priority.
Every rule has a priority assigned to it. When a rule matches the monitor configuration, this option stops running a check on the other rules that have a lesser priority. Thus, when run manually, the disk partition is deleted. But during data collection, the high priority rule matching the condition will get executed.
Solution:
Change the priority of the configuration rule based on matching criteria. In the Site24x7 web client, go to Admin > Inventory > Configuration Rules.
Note: The least number has the highest priority.