Please have the option of having the backlight on all the time. Your fiddly method of 30 minutes worked exactly once, the reverted to five seconds.

I have the keyboard plugged in, so I don't care about battery use.

Logitech used to be good. That's why I bought this keyboard today. Instead, I am taking this back to the store tomorrow, and will noe but Logitech again.

There are dozens of complaints about this matter on the internet. Please, please, please listen to your customers.