How much ram do you have? How large is the swap on disk?
You are aware, I hope, that unless you tell fedora otherwise it only creates a 4G zram swap in memory and no swap on disk. Without the on-disk swap at least as large as your RAM you cannot suspend to disk nor hibernate.
Lack of adequate swap space can certainly prevent suspend to disk as you mention with the unencrypted drive. It may also cause the immediate restart when encrypted due to the failure to suspend.