Nicole,
MESSAGE1 CONTAINS "DRF Backup or Restore process has failed" should be enough to raise an alert for any incoming message, regardless of what server it is coming from. If CFAC field is showing EMPTY, you don't have to include in the where-clause. For this simple text matching, we don't have to use regex match.
Moreover, you have further options in the threshold's Message Destination to provide custom text that contains mix of static text and fields from the record. If it works, let us know.
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Thanks,
Shoaib