Error: failed to connect to fly machine: Supposedly started, and not stopped

I am unable to recover udns app (fly deploy) because of a zombie Machine in vin which I can neither remove nor update:

23908066ec6875	udns-vin	started	 :     1970-01-01T00:00:00Z	0001-01-01T00:00:00Z	
# update
➜ fly m update 23908066ec6875 -a udns
Error failed to get VM 23908066ec6875: nats: no responders available for request
# remove
➜ fly m remove 23908066ec6875 -f -a udns
Error could not retrieve machine 23908066ec6875

Is there a way for you folks to get rid of it?