Thanks for posting here in the Google Nest Community.
I know how it feels when something isn’t working as it should. A few things: Are you having issues with your Nest speaker/display? If so, which Nest speaker/display are we working with? Is this the first time that this happened? Were you experiencing any internet outages recently?
You can do a sequential reboot. First, unplug your Nest speakers/ displays for 30 seconds, then do the same thing to your Wi-Fi router to refresh both devices and your Wi-Fi signal. Observe if the issue remains.
Keep me posted.