On my keyboard, I access the Fn Layer 1 by holding CAPS, which then makes my WASD into arrow keys. On the main layer, I have SOCD enabled on A and D.
If I hold CAPS and press A to use the Left Arrow key, it moves the cursor to the left while also registering A, so I get a string of A characters while using the left arrow.
My expected behavior would be for SOCD to apply only to the layer it is set on.