There's still roughly 1 and a half weeks left till the end of the FY (plenty of time IMO), so why will you be loosing hope??? I understand reading about other people's good news can get to someone who like you who is still waiting, but I don't think that is enough reason to start loosing hope at this point. What if you haven't had the interview or bio like
@Ahmedaboesawy2020 who is waiting until next week to do either of those and is still very much positive? So hang in there!
Says who your background check hasn't been triggered? The IO is not the one that conducts the background check, her saying "she did not check our background check yet" simply means she hadn't checked (as at the time of your interview) to see if it had cleared or not. Background check gets triggered the instant the bio gets completed. Doing the bio at a ASC, different from the FO, is the normal process. Clearing the background check process differs from person A to person B like you already know, so yours may be undergoing some additional checks based on whatever the initial check turned up.
Tier 2 rep not seeing anything in the system regarding the completed interview doesn't mean anything, they will not see anything if the IO hasn't updated the system. Yes you can initiate a congressional inquiry and wait to see the response .