Yes, the problem was indeed that my coins get moved when the public key changes. Which means I would have to keep register my new public address with the Byteball bot and sign a message, which is a time consuming task. TryNinja's solution was fine.
Just realise that the private key/address you have generated is NOT included in the 12 word seed you got when you created your Mycelium wallet. As such, it is NOT recoverable with the seed words should you lose your phone.Make sure you have secure backups of that private key, write it down offline somewhere safe... if you don't and your phone is lost/stolen/broken... any coins in that address (which I'm going to assume is most/all of your coins on June 9th) will be lost forever.
