In Mac OS X Catalina, Apple introduced a Notarization of software requirement. More details can be read here.
Even though the Backup Agent for MAC should install and function properly on build 12.5.14800 , the OS would still produce a warning that the software could not be checked for malware:
"X can't be opened because Apple cannot check it for malicious software.
This software needs to be updated. Contact the developer for more information."
The issue has been fixed in version 9.0.