I'm glad Meter published this post as I've been fighting this issue for the last couple of weeks and wasn't able to find much information on the root cause.

I started getting packet loss recently, and after being unable to find the cause, I tried upgrading my router. That somehow made things worse -- rather than intermittent packet loss, it would get into a completely unavailable state and not recover. I couldn't even switch to other networks without restarting wifi.

This affected multiple M1 machines and an iPhone, so I was quite sure it was an Apple issue, but wasn't able to find the root-cause. After some limited testing, I'm pretty sure this issue caused both my intermittent packet loss as well as complete downtime.