Cannot delete old Bluetooth pairings when Bluetooth is off

[Robie Basak]

I'm running OTA9 on an Aquaris 4.5, having upgraded yesterday. Since this includes a BlueZ upgrade, I thought I'd try pairing with my car again, since it paired but didn't work properly before, and I thought I'd try again given that there's a chance it might work now. However I cannot delete my old Bluetooth pairings.

If I go to System Settings->Bluetooth, I see to pairings under "Connect automatically when detected", which correspond to my two previous cars. If I choose one of them, there's a button "Forget this device". But it doesn't work. When I press the button, I'm taken back to the Bluetooth summary page but the device is still there under "Connect automatically when detected".

Note that this was with Bluetooth turned off (so the slider at the top labelled "Bluetooth" is off). When I turn Bluetooth on, deleting pairings work.

Expected behaviour: either allow me to delete pairings, or don't allow me to think that I can delete them when Bluetooth is off by disabling the option or something.