Phantom Airbnb Booking on My Account

I woke up to a strange string of notifications — “I” booked a home in Austria, was charged 500 euros on my PayPal, but then the booking was canceled and the charge was reversed. I changed my passwords immediately and called support, and they said that everything was fine but couldn’t give me any more info on how this could have happened. I know that it’s all fine and I’m not being charged but I’m just curious how this can occur. Based on my “Recently Viewed”, I see that whoever used my account had access to it for a month as they were searching for apartments sporadically, all over Europe… Spain, Austria, Germany… I have 2FA on — I never received any texts about anyone logging into my account. Anyone have the same experience? What is the modus operandi? Why did they wait so long to book something? Why did they cancel the booking on their own, or why didn’t they try to lock me out of my own account? In my view, it feels like someone was using my account thinking it was theirs, no malicious intent… but I never logged into a public computer with this account so idk!