“Hide my email” messages not delivered

The same issue is happening to me. None of those Hide My Email with Sign in with Apple forward emails. It did seem to receive emails sent from the same domain of the site I registered with Apple using HME though.

When I logged in to https://www.icloud.com/icloudplus/, I saw only one active address (with a paragraph and link guiding me to manage those Sign in with Apple emails. There's not much "management" you can do there, only turn off the forwarding and stop using Sign in with Apple. Which means you will have to create a new account and lose the original account.)

I tried sending an email to that one active address, and the forward worked. I thought maybe I could add those Sign in with Apple emails to that list, but NOPE! There is no such option! Once you click the Add button, it is only creating a new email for you. It won't help release the hijacked email. Please do something, Apple!