Duplicate alerts where generated for the same instance without the previous alarm being cleared by a user or the rule itself. If the rule condition changes, the rule clears the alarm and it would be regenerated, if condition matches again.
If the 10k internal processing limit for alarms is reached, you might be hitting a problem where not all alarms are considered when the conditions are checked.
Please follow the steps below to increase the limit temporary:
DO NOT restart the FMS afterwards. The change it not written in the FMS DB, it is only persistent in the FMS cache.
To make the change persistent, modify the server.config file like described below: