Thanks for getting in touch, and welcome!
I’m sorry to see you’re hitting this unexpected issue. When the custom installation directory feature is used, the Tentacle retention policy will not run against that directory as it’s assumed a working release is contained in it. However the standard default directories should have retention applied against them (deleting data attached to releases that fall outside of the defined range in your policy). I’m not sure of the reason why you’re seeing this unexpected issue, but I’d like to have a closer look.
Would you be willing to share a copy of your task log from the latest deployment? This retention policy is run during a deployment, and there should be some details as to what’s deleted, what’s not, and why, in it that might help shed some light on this.
I look forward to hearing back!