Fn key works differently on new keyboard in TESO

I have a Text Edit Super Object with “Terminate when Return” unchecked. On my MacBook Pro’s internal keyboard and my now defunct Apple Wireless Keyboard, fn+return closes the TESO. This is the behavior I am used to and want.

My Apple Wireless Keyboard stopped working and I replaced it with a Logitech K811 bluetooth keyboard. On the Logitech fn+return does not close the TESO. It is as if the fn key is ignored when pressed with the return key. I installed the Logitech Options System Preference Pane, but it does not appear to address this use of the fn key.

What “key” is sent by Apple’s keyboard when fn+return is pressed?
Is there a way to get the Logitech keyboard to send the same key?
Is there another way to close a TESO via the keyboard? (The tab key can be set to close the TESO, but it opens the next TESO, which is not what I want in this case).

Thanks.

fn-return is the MBP equivalent for the Enter key.