Something similar happened to me this last February: I had a 5 week rental in Baja Sur (Mexico). Due to a serious medical emergency (covid booster vaccine gave me ischemic lacunar stroke) I was hospitalized 2 days before my trip and hence had to cancel it. You can imagine, in the middle of the hospital brain fog and all, I just cancelled through the standard process without thinking twice.
Days later after I was stable and out of the hospital, I found out that the cancellation gave me back I think $200 usd of the around $2000 I had paid....
At some level I kind of felt it as abusive. But I'm sure there are enough small prints somewhere to which I agreed to that explain why it's OK. And given my health issue I decided not to worry about that (puts things in perspective haha). I was more sad that I had to cancel the vacation/trip my wife and I planned, due to that emergency.