Further follow up:
I managed to get this sorted. It turns out that the "hosted-engine --deploy --4"
command was causing the issue. By removing the "--4" flag (even though we
don't use IPv6), and letting the deployment script complain about duel-stack
environments (to which I had to answer "yes" to continue the deployment) the
script then went through its process OK - even doing the dnf updates.
Hope this helps someone in the future.
Cheers
Dulux-Oz