I have an Nvidia Shield. I use a Logitech Harmony Hub instead of the remote the Shield comes with. I do not have the Shield game controller. In order to use the assistant, I used an old webcam's microphone as described here: https://www.reddit.com/r/AndroidTV/comments/79z8s6/usb_microphone_for_ok_google_on_nvidia_shield_tv/

It worked well, until the Oreo update came along. Now the webcam does not pick up my voice.

Does anybody else have this issue? Is it because of Oreo, or is this Nvidia specific?