Hyper-V Suddenly Stopped Functioning

For no reason I can see, none of my Hyper-V virtual machines will start. This morning they did, now they don't. It looks like a Windows Defender update may have happened in the meantime but disabling the firewall didn't help. I have 4 virtual machines, 3 windows 10, one windows 11. None of them will start with "cannot connect to the virtual machine. try to connect again..."

And if I create a new virtual machine it won't start either.  Basically, Hyper-V stopped functioning from one session of using the computer this morning to this afternoon, no changes made by myself.

Another thing that happened as of yesterday is that I'm getting a notice that there are two devices with the same IP on my home network. Not sure if there's a connection to the Hyper-V thing but I don't know how to fix that either.