Booking.com had an outage, causing issues with Reservations.
Started :- 2025-09-16, 12:55:39 AM UTC
End :- 2025-09-16, 02:33:50 AM UTC.
The issue has been resolved and all services are now back up and reservations should now be communicated normally.
If you have any issues with the delay/bookings/overbookings, then please contact Booking.com for assistance.