Bluetooth mouse not recognized El Capitan

The problem is the detection of my new Logitech MX Master mouse, which has both Unifying receiver and Bluetooth Smart connectivity, which are supposed to work independently depending which you choose. The mouse has 3 possible Bluetooth channels (to remember 3 different pairings).

BUT for some reason there's a problem with the detection of my mouse device using the built-in Bluetooth. I updated my MacBook Pro (Retina, 15", medio 2014) to OS X El Capitan 10.11 before trying to connect the new mouse, and my other previous Bluetooth devices work just perfect. I have "Logitech Options" v. 5.30.150 installed as well.

Solutions I have tried already with no luck:

1. Connecting the device following Logitech's guide
2. Deleting all existing connected Bluetooth devices from Bluetooth preferences > rebooting > trying to connect the mouse again
3. Disconnecting all peripheral connections, USB, Unifying receiver etc before trying to connect mouse
4. Disabling Wi-Fi while trying to detect bluetooth mouse (due to other Wi-Fi Bluetooth discussions I've seen)
5. I have no problem connecting other Bluetooth Smart products (Logitech keyboard, speakers etc.)

I want to make sure it's not just an "El Capitan"-problem before I return the mouse for a replacement.

Hope you're able to help! - Thanks