Deactivate hide my email not working

I’ve been trying to deactivate a number of hide my email addresses that I haven’t used in years, but it’s not working. I tap the address, then “Deactivate email address”, then “Deactivate”. But then I get a notice “Stop email failed. Invalid request for private email”. This is happening for every address I try to deactivate, some up to 5 years old, others just a few months old. Can anyone advise please?