I went over the alert raw file and was able to confirm that the duplicates are a result of alerts being sent to the ConnectorAccelerator connector with the alertKey value.
If you send alerts with the alertKey value, the ConnectorAccelerator will use the alertKey value as part of the Source Alert ID.
I found that those duplicate alerts have different alertKey values.
Example:
Source Alert ID
XXXX.XXXX.net-KR82070387-33119
palld4nexrepos1.broadridge.net-US58429468-00750
Summary:
UIM:BR:Robot XXXX.XXXX.XXXX is inactive
UIM:BR:Robot XXXX.XXXX.XXXX is inactive