Connecting CD player to optical input

Hi there. Node 2i appears to be doing something strange to the 44.1khz signal from both my CD player and minidisc player when they are connected to the optical input. If I connect either device directly to my DAC (cutting out the node completely), the DAC shows a 44.1khz signal as expected. When I connect a CD player to the node via the optical input (same cable as before but adding the 3.5mm adaptor) then a) I see the optical input option in the controller, but I cannot select it (I see the spinning circle saying it's searching) and b) the DAC shows a 48khz signal when it should show 44.1khz. There is no sound from the node. The DAC can deal with a regular 48khz sample rate ok, but not from the node it seems. What is the node doing to the 44.1khz input signal such that the DAC receives a 48khz signal? How can I get the node to pass the 44.1khz signal from the optical input to the optical output? All other node inputs (USB/network files/online streaming services) pass the correct sample rate, it's just the optical input that's being altered. Thanks in advance.