The goal release:branch doesn't work as release:prepare with multi-module projects with flat layout (with parent project and modules at same level in URL path)
While release:prepare takes into account the project layout using ReleaseUtil.createBasedirAlignedReleaseDescriptor, the goal release:branch doesn't
The involved calss is org.apache.maven.shared.release.phase.ScmBranchPhase which is similar to org.apache.maven.shared.release.phase.ScmTagPhase, so I've assumed I can invoke ReleaseUtil.createBasedirAlignedReleaseDescriptor to obtain the corrected ReleaseDescriptor.
I've corrected this behaviour in a local copy of maven-release-manager module and seems to work, but i have not fully tested the patch
The patch is relative to maven-release-manager module