Master Lock Code request?

Im just updated from 16.1 to 17.0 on my Fire Stick but in Settings I can’t access Profile Settings as i’m always prompted to enter a Master Lock Code, despite the fact I haven’t set one.

In Interface Settings there is a Master Lock tab, but I need to enter a Master Lock Code to enter.

Anyone know if there is a default code, as I certainly haven’t set one up.

Thanks