What is a bank going to do when inflation is at 7% but has loans at 5%? If the bank is in trouble it will call in it's 5% loans. Wouldn't you? What if inflation is at 20%? Think the banks can afford to lose 15% on hundres of billions of dollars? I don't.
Show me *one* example of an American bank calling a *performing* home mortgage due to foreign exchange Dollar devaluation.
You can't do it (because you are making up "jpsb economics" out of your butt).