Strange HP-31E Function

[aj04062]

I am not sure how to describe this, but I have a 31E that works like a currency adder. In other words:
enter 999
and the calculator interprets this as 9.99
no matter what I enter, the decimal is fixed one place from the left.

However, if I multiply the value, the decimal place will shift to the right and the commas appear where they are supposed to.

If I enter a value using scientific notation, the calculator displays the decimal correctly (when in Fixed mode)

It passes the self test.

My other 31E does not function like this.

Ideas?