Looks like your cars Kubernetes certificates have expired after a year, we'll need to SSH in and run kubeadm to refresh them. Wait, the 5G pod isn't starting ...
You joke, but I decided I wanted to try out Kubernetes, so I set it up at home and moved some of my local services into it, one of them being my custom lighting automation software. Eventually my lights just stopped working, and after a lot of rummaging it turned out to be expired certificates. I promptly put the software back where it was before, removed Kubernetes, and decided there were better things for me to play around with.