Can’t tell what exactly they think is in UF. Perhaps you mean the principle is in UF? That’s pretty meaningless though. The actual loan amount is converted to pesos when it’s finalized (the process can take months), and the APR is just some percentage of that.
Source: Live in Chile, have mortgage in Chile in pesos.
??
On this recent Reddit post in /r/Chile someone asks “does anyone know if there is a bank which offers mortgages in pesos instead of UF?”
The answers all pretty much say they don’t even exist, or if the poster finds one to please let them know
https://www.reddit.com/r/chile/comments/1ep21lq/hipotecario_...
It looks like Chileans have never seen a mortgage _not_ in UF