Yes, the A-record solves the redirect from http to www. with HTTPS.
But to connect to naked HTTPS and see the redirect to
www., the naked HTTPS must first be working and responding to requests. For that you need a separate server, or just let cloudflare take care of it using their DNS.
CB did not make ssl certificate for the naked domain, therefore the HTTPS versjon of it is not existing until you do something.. many have their main site there already so cb cannot make certificate for it.
Sorry i am not so good explaining but i got it working using cloudflare alone.