Yes that’s correct, the SSD is external via 3.1 type c. Dom0 hasn’t crashed trying to start sys-firewall, sys-firewall still won’t start.
Do you have any other suggestions to try?
if you have another cable you might want to try changing first, but if the problem is because power lost, it should be the entire system is crash. Your case is only some, btw can you boot up template ? give the template sys-net netvm, and then try running firefox there. do you have any problem ?