Weird streak on negative

After developing my second roll of Rollei ATP 1.1 this weird streak is very apparent. It covers frames 1-18, is intermittent, and is almost perfectly straight down the roll. My first thought was a light leak, but that would be black. It kind of looks like horrible scratches. Could my camera have done this damage? I've never seen anything like it.

Sorry for the poor quality pictures. I don't have a scanner so I just snapped one photo with my phone and another one with a loupe. In these images it looks like a solid streak. In the first 10 frames though the line is clearly broken. The "scratches" almost line up with the sprocket holes but only for a couple frames.

Is there any actual physical damage to the negatives? As in, when you run your fingers over the negatives, is there a scratch or blip that indicates it is damaged? It is hard (but not impossible) to get a consistent scratch during development, although if commercially developed, I have seen these scratches from dirt/dust on rollers.

Did you squeegee the film? Use Photoflo?

It looks like abrasion, like material has been removed since the line is lighter than the base.

I never squeegee (purposely don't own one) and always use Photoflo. Nary a problem in decades.

Could it be some weird half-height solution thing where the film is bathed top and bottom but a line of bubbles is preventing development at the middle? I rate this as a highly unlikely hypothesis.

Did a line of grease (hand grease, nose oil, etc.) get onto it when loading the film onto the reels? Plastic / nylon reels or stainless steel?

Is the film fogged or is that natural clear base density?

Is the physical scratch on the emulsion side [rollers, film cartridge] or the back side [pressure plate]?

I always use PhotoFlo and never use a squeegee.

I did not squeegee. I used Ilfotol wetting agent and hung to dry.

After closer inspection the film feels very smooth, so I don't think it is a physical scratch, at least not a deep one. I can't determine if it's on the emulsion side or not. However, because the negatives are especially clear at these blemishes I'm tempted to say the emulsion was physically harmed. The color in the images is due to my light box. The film base is almost perfectly clear, just like my first roll of ATP.

Also, I noticed there are a few other streaks that are less pronounced. Some are above, others below the big nasty one, and they are much shorter and thinner.

I suppose some oil from my fingers could have found its way onto the film when loading, or perhaps on the cartridge, but the harshness of the streak in several places (somewhat visible in the loupe image) also makes me think scratch. I'm using the Paterson Super System 4. Considering the big streak is 18 frames long I'm going to look very closely at the cartridge, and then clean my camera again.

It doesn't look like a scratch. And a scratch that gouged out enough emulsion would be very prominent. Scratches before processing often have a black border to them where the scratch 'exposed' some of the silver grains by mechanical action.

I would hazard a guess it's an emulsion defect.

If it is not a scratch then it is very odd that it is lighter than the film base.

Did this happen only on this roll or on more than one? I wasn't quite clear, sorry, if this was your second roll on which this happened.

I would try to develop a black roll, see what you get. That might tell you if it's your camera or the film.

This was the only roll with the blemish. It's only the second roll of ATP 1.1 that I've developed (the first one was fine), but I've developed plenty of other types of film without any problems. Hopefully it was just a defect in this one roll.

I lined up a strip of negatives in my camera, and the streak seems to align almost perfectly with an edge on the spool that advances the film. If that is the problem, then the next 2 rolls I shot tonight may show the same streak. It is quite odd though that only one of hundreds of rolls would be scratched by that spool's edge. Is the emulsion of ATP particularly soft?

Which spool do you refer to?
The sprocket assembly for advancing film should have a plain axle and the film rebates should run over the plain circumferences of the sprocket parts. How could this assembly touch the image section?

Sometimes material gets trapped in the felt light trap of the film cartridge. Sometimes, but rarely, debris will get stuck on the pressure plate. Since this was a one time problem, it was a processing error or the light trap got some dirt.

Keep film in cans before and after exposure. Most roller transport lines pull film through the felt trap a second time. Keep your camera clean.