“I have around 150,000 Iron Points in my JEFIT account, but only about 130,000 show as consumable when I try to redeem them toward Elite. Can you explain the difference between total Iron Points and consumable points, and why there’s a gap of about 20,000 between the two?”
Consumable points are those Iron Points you have not yet used towards Elite subscription weeks.
So in your case you must of used 20,000 points at sometime in the past.