The issue was found and fixed with Release.Manager 9.0.1 in Release Manager. The Package is available for download at the Automic-Support-Zone (https://support.automic.com).
Hotfix-Description: Workflows are triggered while upgrading Packages to a new Custom type version
A problem has been fixed where workflows were triggered during the upgrade of Packages to a higher Custom type version.
While upgrading Packages to a new Custom type version, the transition workflow was re-executed even though the Package state did not change.
The fixes also provided in below version
Release.Manager 8.0.4,Release.Manager 10.0.0,Release.Manager 9.0.1