Why don't I see some of the backed up hard drives on backblaze.com?

Question

I am looking at some Backblaze account with the 1-Year Version History option activated over 1 year ago. The Backblaze Windows client indicates that at least one file from external hard drives with letters H, I, J, L was uploaded less than 1 year ago:

The full value of the status column is (Unplugged).

However, I don't see the external hard drives with letters H, I, J, L on https://www.backblaze.com/:

Why? Why don't I see some of the backed up hard drives on https://www.backblaze.com/?

I tried to change the date in the "view/restore files" screen to an earlier date when those drives were connected and backed up, but that didn't help:

The external hard drives with letters H, I, J, L were showing up in Backblaze fine earlier this year.

Answer 1

Keith Langmead pointed to help.backblaze.com:

With Extended Version history, files removed over 30 days ago, or external drives disconnected for longer than 30 days will be retained on our servers; however, if files/drives have not been present for longer than 30 days they will not appear in your current backup view. You can adjust the date and time preferences in your View/Restore Files section to locate data that has been deleted, overwritten, or otherwise removed from the computer being backed up.

Changing the date in the View/Restore Files section fixed the issue:

A former Backblaze employee shared the rationale here.

Note that help.backblaze.com is incorrect. It says:

if files/drives have not been present for longer than 30 days they will not appear in your current backup view.

It is in fact not 30 days, but 90 days, as former Backblaze CTO Brian Wilson stated, which I confirm: e.g., 69 days for disk M on https://i.sstatic.net/14LS5.png.