Who lost money in this situation?

edit: I know currency fluctuates. That’s why I referenced it in the original post. I know the AUD depreciated between the two purchases. The question is: where did the extra $20 in my pocket come from (ie credit card company, hotel, etc)?

I booked a hotel for 350USD in November 2024 that was recorded on my credit card statement as 540AUD.

This week i cancelled the booking and was refunded 560AUD.

Nice for me, making $20 accidental profit through foreign currency refund arbitrage through a weakening AUD.

But who loses in this situation? The hotel presumably refunded the same amount of USD as the purchase price (350USD) and is therefore unaffected, so where did that 20AUD come from?