Apple Mail: Moving self-CC'd email removes from Sent

Hi

I am using Apple Mail on iPad and iPhone.

When sending an email, if I cc myself, as expected it appears in my inbox and sent items.

If I then move that email from my inbox to another folder, it disappears from the sent items folder.

Outlook works perfectly and keeps both copies.

Is there some setting I can change so Apple Mail keeps both copies, or is that how Apple Mail works?

Thanks

Mark