Probably just met their daily quota already or reduced staff due to CNY. Who knows. They make it up as they go sometimes. All you Can do is do what you were told to do...😁

Did this just last week, first time at BKK Io. IMO definitely worthwhile booking an online appointment. Get copies and photo done before you go. It will save some time and effort having to negotiate what can be a daunting large building you are not familiar with. Give yourself a good 15 minutes before appointment time to get application and fill out. Take pen, glue is readily available to attach photo to form. Pro tip. If you make an appointment you do not need to get a number for the queue. Go straight to J 24,25 and politely let it be known that you have an appointment. It's a bit confusing because there doesn't seem to be a procedure for calling identifying online appointments. So if you don't make yourself known you will be left looking at the ticket numbers been called before you. With an appointment I was in and out in 15 minutes last Tuesday. Good luck 🙂