In case of sds....When your review of eligibility started ,firstly your medical passed, then they verified your LOA and GIC, IELTS... after all verifications they review you are eligible for study permit or not and then decision made on your file.... All this take some time not instantly they can give decision, therefore after one or two days of review of eligibility they cannot make decision.... that what was happened to 3rd and 4th September AIP recipients....only one day ago their eligibility started and eveyone received AIP