We have multiple configurations having "Build Celeanup Strategy" set to 7 days and "Artifact Cleanup Strategy" set to 5 builds to remove the artifacts pretty soon as they are only intermediate artifacts used in later stages of the build pipeline.

Since upgrading from 6.1.18 to 6.1.31, the artifacts are no longer removed, but kept until whole build gets removed after 7 days. Upgrading to 6.1.34 did not solve the problem!