I have a similar situation. My case was considered for less complex in April 2024 and was moved back to regular hearing. I still have not received a hearing date as of today…..maybe it’s just luck but I would suggest you buckle in cause it might be a while. ♀️
Have you tried just calling the IRB and asking what the current status is? They are usually pretty good at answering their phone during working hours and would be able to tell you if it (security check) is completed or not.