That tells me that you are running through the Windows command prompt and not WSL (i.e. there should be a separate “app” icon for you to launch WSL. In my case I have an icon for Ubuntu 18.04 LTS. The thread I linked you above describes this (note the screen-shot of the icons). To clarify, on my Windows 10 setup:
That is, it appears that you have installed a Windows 10 version of conda, not the Linux version of conda, which should be installed within WSL Terminal as is outlined in the thread I linked above. Does this make sense?