Jim, is the Oxygen 25 highlighted in your input window? If it is not then it is not going to work.
Did you try this, power down your computer. Unplug your Oxygen. Boot your computer then plug in the Oxygen. Did it work?
I have had a Win 10 update delete a driver before. You might want to DL the latest Oxygen 25 win 10 driver:
https://m-audio.com/support/driversI hope this helps and good luck.