Logitech K780 Frequently Asked Questions Manual page 21

If you don't allow KEXT loading, all devices supported by LCC will not be detected by
NOTE:
software. For Logitech Options, you need to perform this operation if you're using following
devices:

T651 Rechargeable trackpad

Solar Keyboard K760

K811 Bluetooth keyboard

T630/T631 Touch mouse

Bluetooth Mouse M557/M558
 +Logitech Options issues when Secure Input is enabled
Ideally, Secure Input should only be enabled while the cursor is active in a sensitive information
field, such as when you enter a password, and should be disabled right after you leave the
password field. However, some applications may leave the Secure Input state enabled. In that
case, you may experience the following issues with devices supported by Logitech Options:

When the device is paired in Bluetooth mode, it's either not detected by Logitech Options
or none of the software-assigned features work (basic device functionality will
continue to work, however).