I have major problem with step of retention policy on Octopus 3.3.20. I already read similar topics about this issue and I have not seen clear description, bellow I added configuration how we made set up for couple channels, both are almost same except channel names.
Channel: ProjectA, Lifecycle: TestA, Environment: Dev, Machine: DevHost
Channel: ProjectB, Lifecycle: TestA, Environment: Dev, Machine: DevHost
Policy retention: keep one release
When deployment are running on environment Dev with steps of ProjectA channel, during at last step of retention policy for some reason it removes previously deployed releases from ProjectB channel and same behavior happened when we try to deploy ProjectB. One curious thing are log records, similar records appears after both deployments, look bellow screenshot.