Does USCIS skip certain standalone I-130 cases?

My PD is September 3rd, 2023 and my standalone I-130 is currently at the California service center. I’m a USC petitioning for my spouse and there’s nothing odd about my case from what I’m aware.

Does USCIS simply skip over certain cases? It seems like they’re now processing mid-September 2023 cases and I’m seeing cases later than mine being approved from the CSC.