I was having issues with OctoPrint not being seen from Cura, so I decided that perhaps something I recently did with plugins where I disabled/enabled some had broken something and that I should revert to a previous backup. I made a new backup and reverted to the previous one. It restored successfully but it made no difference, Cura was still not seeing it.
To my surprise however I then found that not only had the new backup I made just before now been lost by the restore, but so had all the other backups.
Did I miss a warning about this when I did the restore? If not, then perhaps there should be one or better still maybe don't delete backups - I couldn't see an option, but maybe the ability to specify a location outside of OctoPrint for the backups would make this simpler so that a restore needs not worry about them.
In the end I made a new backup, downloaded it then completely wiped the SD card of my Raspberry Pi and restored the backup to the new install. It again restored just fine but didn't fix my Cura issue - it still cannot find OctoPrint, and neither can any of my Windows PCs, but entering the server details manually fixed the issue.