ZEDi-10FX USB setup - music from the browser?

I am pretty new at this so have started very simply. I have installed the latest ASIO driver from A&H on my Windows 10 PC along with Cakewalk legacy version. I have a mic connected on M1. Backing music is to be played via browser. The idea is to play the backing track via the browser (easier to make quick tempo/pitch changes), record a vocal, and save both as separate tracks. I assume that there would be no issues with just importing the audio file into the track, so the question is whether this can be done by playing the audio file from the browser? I have been using Grok AI to suggest settings, etc.

The problem is that with the suggested USB Out setting on the ZEDi10 of M1-M2-M3-M4, There is no input to the Cakewalk track. If I set M1-M2-L-R button to down, then there is input, but there is a bleed-over problem, as Grok predicted.

Settings are as follows…

PC Sound:
Output - ZEDi10 ST3
Input - ZEDi10 M1

Cakewalk:
Preferences/Audio/Devices - All devices checked

All input and suggestions will be greatly appreciated.