Hi @Caitlin363
It sounds like the luxury Airbnb must have had a very high price set for the extra night that you added at the end, while at the first Airbnb the extra night was just $8 more expensive than the night that you had canceled. The very expensive added night at the 2nd listing could have been manually set that way by the host, or smart pricing could have increased it automatically due to high demand. You can message the host and ask about it - if they are willing to drop the price back to your original total they can refund you using the "send money" function after you have checked in. If it is really a very popular night due to something like an event, they may be reluctant, but you can try!
The other possibility is that the second Airbnb may use a stricter cancelation policy and that you were not fully refunded (or not refunded at all) for the canceled night. You should click on the reservation to see the exact calculation of the new price. You can still discuss a refund with the host and argue that you are staying the same number of nights.
The bottom line is that you have accepted the revised total, so there's unfortunately no guarantee that the host will give a refund.