What causes an alert to get automatically associated with an incident?

[Alex Edwards]

OpsGenie appears to automatically associate ALL alerts with whatever incident happens to be open at the time for the service.  What causes that and how do I turn it off?

Obviously it should be possible to have multiple simultaneous incidents for a single service.

So for instance, if I have a datadog generated alert occur and an incident is created from that alert.  Then if I create an entirely separate alert via Jira integration, OpsGenie will do zero notifications for that alert because it associates it with the incident created by the datadog alert.

That is not great because the second alert is entirely unrelated to the first alert/incident!

[Riley Venable]

If an alert automatically matches an incident because of an incident rule, after the incident status is resolved, the incident status will be changed from resolved to reopened. Therefore, it is important to close your incidents in a timely manner, because notifications are not sent for alerts matching an open incident.