See update below.
How do I change the IP address for my QNAP NAS? I set it up as the default backup location and everything was working properly but I had to reconfigure my network to fix some issues with streaming on my Nvidia Shield. Now when I go into the Settings/System/Backups it doesn’t list any backups (even the older ones from before changing to the NAS). The 3-dot menu in the upper right has a “Change default backup location” option but it shows the NAS with the old IP address and it doesn’t let me edit or delete this. The only option it provides is to change to a data disk (USB stick?). There are no edit, delete or new location options so all of my old backups are not accessible and I can’t create new backups since the old IP address doesn’t exist now.
Update: I was able to create a backup on a USB stick then I updated my HA operating system. When that was done a new “Repair” item appeared above the “Updates” list. Selecting this opened a dialog box for the NAS location and I was able to update the IP address. The repair was successful and I now have access to all of my older backups and can create new ones on the NAS.
Bottom Line: It would be much easier and cause less confusion if there was an option in the " Change default backup location" menu selection.