Is my Time Machine backup encrypted or not? As you can see, I use Time Machine to backup on drive "Data" on "ZRH" which is a Time Capsule. To the best of my knowledge, I selected "Encrypt backups" when I configured this backup a few weeks ago. But as I have a look into the configuration, the box "Encrypt backups" is not checked.

I wonder whether my backup is actually not encrypted or whether this is just sort of a "bug" in the configuration menu that the checkbox does not show the actual encryption state.

I have File Vault enabled.

(Trial and error is not an option in this case, since it's a 500 GB backup which would take forever to rebuild.)

It would already help if a few of you could just have a look into their backup configuration and check whether the checkbox is checked for encrypted backups.
I deleted the old backup and created a new one, with encryption on: 

Yes, the checkbox in the above screenshot is displayed as checked if the backup is encrypted.