AR Transaction reversed from last year which should book currency gain loss did not

We created a Free Text credit memo last July.  In May the transaction was reversed.  The GL bookings booked only the invoice amounts.  Since this is foreign Currency transaction, it should also be posting a gain/loss as last year it converted at 1060 and this year it was 1106. How does the difference get booked?

We are on R1 CU3.

Thanks for your assistance,

Carol