@Paul875 did they send you a Booking Inquiry first that you had to approve?
I have heard from other hosts that guests can change the check-in and/or check-out times to something different when they make a Inquiry (or was it a Request?).
If the host does not notice the change, when the host Pre-Approves the Inquiry, then for that one guest the check-in and check-out time will be different (if the guest books using that Pre-Approval.)
I have not verified this with anyone because I can't find where it is documented.
But the host who mentioned it had clear screenshots of a very different check-in / check-out time for this one guest.
Does anyone have good information about this?