It is 11 business days, so you need to exclude weekends and holidays. I am confident that 99% take this amount of time. Can you share any posts that were quicker ?
KL is known to ask for these extra documents. That is why many suggest not to apply there. For health, you will need to show your future plan. Usually medical treatment, doctor/hospital and dates of future treatments
My understanding is you are able to submit online, but you will receive an email in a few days (maybe longer because of holiday), that it is actually rejected. What I believe you received is acceptance that they received your submission, not that that it was ultimately accepted. I could be wrong, so others should