Patchng in Fairlight for Zoom L12

Ok, this may seem obvious for some but not for me. My Behringer 20 channel mixer of circa 1995 (the lawsuit version) died a few weeks ago and I made the decision to move to a digital mixer in my edit suite. Though used mostly for monitoring and the occasional scratch track record, I wanted to be able to get the most from my purchase. I rented a Zoom L8, and got it working (sorta) and decided to buy an L12, more inputs, features.
My understanding is that Fairlight would see all of the 14 available tracks on the L12 on the input side and only 4 tracks on the out put side. So I chose those and ticked the boxes.
However, it seems to untick them on its own, only gives me two channels of the four out when I go back after setting it. I lose playback and am generally confused.
All of this to say that I have not been able to find a proper guide to using the Patch page or to setting it up with a NON BM audio interface.
Can anyone direct me?
Thanks
Brian

Have you set the L12 up as the computer's audio device for input and output and switched it to interface mode on the back of the mixer? Resolve uses whatever is setup as the systems sound device. Then in the preferences page of resolve, in the audio i/o section you can set it to 'use system' or manual setup for the speakers.
Are you on windows or mac..?
Here's a quick vid on windows setup with a usb interface, if you are on a mac, the input patching to a track is the same, but setting up the L12 as the system sound device is done in the audio/midi settings.

You'll only get 8 inputs at most on a device using system drivers. The zoom will do more with a program that uses asio drivers, but Resolve doesn't support asio drivers, only system drivers.

Thanks so much for taking the time Andy! Your video and explanation helped make things clearer and I am now using my Zoom L12 to the fullest.
Cheers from Montréal to Melbourne.
Brian