I think you mean Malcolm & Sean (or mswhin63 & AnakChan
).
Ah I see, so you had the filter on for your flats, but you took the filter off for your lights - resulting in flats calibration not appropriately matching for your lights. Good find.
Whilst that pretzel will still exist in the lights, as you've taken Sombrero without any filters (i.e. broadband), that pretzel is effectively "hidden".
You're taking this with a Newt. Sure you're not having any light leaks in the focuser/camera region? Anyway you could shield that part away from the street light? If its truly the streetlight, I can't think of anything else but to reposition your scope (which sounds like a limiting factor for you).
There seems to be a bunch of weirdness with your Sombrero light sub there. I'm not certain if it's solely due to the streetlamp.