Are your spouse's LPP (all three, including prohibitions) cleared?
If prohibitions are not cleared, then I don't think you can say it's not stuck in security.
The exact split between background and prohibitions is not entirely clear to me, but I'm quite certain that at least some of the things in the prohibitions bucket include security issues.
Similarly with PM03 - while PM03 is clearly not a 'high level' position in IRCC staffing, it's also not the lowest, and implies at least some level of authority/judgment required to look at the file and make recommendations. (I believe it doesn't tell us the PM03 /will/ make the final decision, or that necessarily stuck with the PM03 - quite possible any recommendations by the PM03 would need to be confirmed by some functional manager with specific authority, and 'kick up' to higher level of authority / more work for most complicated cases always a possibility).