Is there no onboarding for contract instructors that guide them through setting up their environment for effective online teaching? Someone who has taught remotely would be very aware of how hard it is to get sound and light right. They'd have a pre-flight checklist and spend 10-15 minutes beforehand ensuring everything looked and sounded ok.

Someone who hasn't needs to be trained because it's not like a physical classroom at all.

And of course, teachers need to improvise every day, but if they're not used to doing it then they need coaching on that, too.

For example, whenever I teach remotely, I mail a good pair of wired, directional-mic headphones to every student. I also send them PDFs outlining how to position the light in their room.

I do that because they are unfamiliar with the subtleties of remote interaction and it's going to ruin everyone's experience if students have barriers to participation and feedback.