To select the audio channels that you plan to record, go to the console’s menu “Routing” / “Card Out”.
For example, to record the X32/M32 console’s analog inputs, select “Expansion card outputs 1-8” to “local 1-8“, and so on.
I assume your card records properly. The reason why you see only one file because the uTrack-X32 records to multichannel wav file which contains 32 channels.
Please connect the USB drive with recordings to your computer and start the uTool and use the Import function to “extract” the file to mono wav files.