The medical community is still struggling to find both the cause and the cure for ME/CFS as well as even finding definitive treatments. So far we all have more questions than answers.
Other lists
Possible Causes by the CDC
Autoimmune
ME/CFS has some findings suggesting that the inflammation is from a compromised autoimmune system but is missing other signs, like tissue damage.2
Chronic Fatigue Syndrome: An Autoimmune Disorder of the Neuroendocrine System
Dorsal Root Ganglia
Post mortems have shown inflammation of the dorsal root ganglia by Dr. Charles Lapp
Energy Production System
Busted! Exercise Study Finds Energy Production System is Broken in Chronic Fatigue Syndrome
Possible Causes by the CDC
Genetics
Gut Health
https://drhyman.com/blog/2017/05/08/getting-root-cause-ms-chronic-fatigue-syndrome/
Infections
Mitochondria
CFS – The Central Cause: Mitochondrial Failure by Dr. Sarah Myhill
Neuroendocrine
A paper on the neuroendocrine system as a cause: Neuroendocrine and Immune Contributors to Fatigue
Chronic fatigue syndrome versus neuroendocrineimmune dysfunction syndrome:differential attributions