Have a read of this thread.
What you are seeing is correct.
To revert to a previous hub version you need to do something different. Its about halfway through i think.
Post 32.
Just to clarify somethings.
The backups are just the database on the hub. You can backup and restore this at any point and the hub stores 5 backups, which are taken daily or on reboot for that day.
Firmware is the software running on the hub. You can roll back to the previous firmware via http://hub ip:8081
Backups are somewhat tied to firmware, but in most cases, restoring a backup to a newer firmware should be fine. Restoring a newer backup to older firmware could cause problems.
We are looking at ways we can make firmware roll back more obvious of a choice to help with this confusion. One idea is to provide a link to the rollback tool (port 8081) on the backup and restore page itself.
We appreciate everyone's feedback as we continue to improve and expand Hubitat Elevation.