TL;DR - if you are having trouble with iDrive not backing up - try rebooting the NAS.
Longer version…
I’ve been using iDrive as a backup for a while now.
About 6 months ago it just stopped working. I would get an error saying it timed out even though it never started. There didn’t seem to be anything obvious so I contacted iDrive tech support. They told me to reinstall the app. When I did that I found that all the settings had gone and nothing matched up with the iDrive backup anymore. At that point they told me I had to start again from scratch. Given that I was backing up 6TB over the internet, I’m sure you can understand that it took a while.
A few days ago it started again. Same message but if I tried to start the backup manually it would tell me it couldn’t do it because an Archive Cleanup is in progress.
I called tech support and received the same reinstall suggestion. I told them I was not going to do that again and so he went away and did a bit more digging. Eventually he told me to reboot the NAS. That’s not something I do very often but I tried it and…everything started working again. So, if you find your self in the same boat - this might help.
On a different note - my iDrive subscription is up in a few weeks so I might switch to another. Backblaze seems to be well regarded…