I do not know what, if anything, is causing your application to be delayed longer than others.
I also do not know what your copy of GCMS records shows, but the local office officials who are processing a citizenship application should not be sending an applicant's info to CSIS UNLESS they are making a referral based on information indicating a security concern. That is, if local office officials are sending info to CSIS that is really, really bad news, since it means there is a particularized suspicion the applicant is involved in something very serious, serious enough to be comparable to terrorism, crimes against humanity, or war crimes. Any such referral would likely result in the application being suspended and at best a delay way, way longer than the excessive delays currently being experienced by many. (Moreover, any such referral from IRCC to CSIS is very unlikely, since if the officials processing the citizenship application come across information which would trigger this sort of thing, they will more likely refer that to CBSA, and if in turn CBSA's NSSD develops information, in its investigation, that rises to the level of engaging CSIS, then it will be CBSA that makes that sort of referral to CSIS.)
The interaction between IRCC officials processing citizenship applications and CSIS should be minimal. There is the initial referral made at CPC-Sydney, requesting a clearance (report of no security issues), which would ordinarily only contain sufficient information about the applicant to positively identify them. Then, for some applicants (depending on length of processing and potentially other factors), the local IRCC office may make a referral requesting an update of the clearance.
There is a great deal of misplaced attention in this forum regarding the formal background clearances, as to the RCMP and CSIS. There is almost NOTHING to be learned from most applicants' GCMS records in regards to the clearances which will provide any insight into the status of processing the citizenship application, virtually none that will indicate what will happen next or when. Despite all the micro-monitoring of such details by so many forum participants.
Meanwhile, prohibitions remain open right up to the day of the oath. A driving while impaired arrest the night before the oath is scheduled will constitute a prohibition, for example, and preclude taking the oath. The third formal clearance required, the GCMS clearance, is done repeatedly during the processing of the application, including at latest when the oath is scheduled. It includes a name record screening for criminal records, which covers both RCMP and the U.S. NCIC (same as FBI records), at the least. Even if the client's GCMS shows prohibitions as complete, that can change anytime right up to taking the oath (for example, a delay in processing may result in the need for a clearance update, so what was marked as complete earlier can then be open until the update is obtained . . . noting that even when RCMP or CSIS have sent the updated clearance to the file, for it to show completed in the client's GCMS will still wait on a processing agent making that notation, typically done attendant other tasks).