Why is my pool listed multiple times in Daedalus?

A. The registry is about pool OWNERS

One important thing to keep in mind is that the registry contains the registered metadata of individual pool owners (identified via their owner public key). A single owner may have multiple pools: Should several pools be registered on chain under the same owner, the pools can show up in Daedalus with the same metadata.

B. Old pools have to be retired

Registering a new pool with an existing owner key doesn't automatically void the previous registration tied to that key. As a pool operator, you must explicitly retire pools you want removed from the list. The creation of retirement certificate is not yet supported by jcli but should be available soon. Please refer to the official repository regarding pool retirement: https://github.com/input-output-hk/jormungandr.