Google / Nest in an email to customers:
In response to community issues caused by COVID-19, we’re temporarily adjusting your camera quality and bandwidth in an effort to conserve internet resources.
With so many people working and attending school from home, we’re stretching our resources in ways we haven’t before—including the internet. As local internet resources are stretched past their limits, you and many others may have noticed interruptions like dropped video calls or frozen screens. During this time, it’s critical for us to work together to ensure we find ways to help the community at large.
To answer the global call from ISPs to prioritize bandwidth for learning and working, in the next few days we’re going to be adjusting the quality and bandwidth setting on Nest cameras to the default setting.
This can be changed back manually on a per-camera basis.