You’re the first person to report a problem with the Hashicorp vault deployment task so I’m guessing you could be the first to use ti with the cloud version rather than a locally hosted version (which is what this was built with). Note that you can of course use a Powershell scripting task etc to run your own commands rather than relying on our built-in task.
Here’s the code that runs to push a cert to a vault:
It looks like we can either modify the task to allow you to specify an optional namespace which we then pass an http header, or the simplest/quickest alternative is you can specify the vault secret path with the namespace as a prefix e.g. instead of /secret/data/mycert you could use /namespace/secret/data/mycert