This looks to me like a badly smeared lens, I have taken loads of photos with this much contrast and never seen blooming like this, but dirty lenses (or damaged coatings on my cheaper old film cameras) give exactly this effect.
As Mike Sowsun said in the comments, a cheap or dirty filter could also have this effect.
The effect will in fact be consistent across the image; it's just the case that it will show up more in the brighter areas.
This is how starburst filters work; all light is affected by the filter to the same degree, but only the highlights will have visible stars as they have such high contrast compared to the rest of the scene.
Here is a good read on flare: https://photographylife.com/what-is-ghosting-and-flare (far too long to copy I'm afraid, consider it background reading :)
Re: coatings and flare not related to dirt, I'm no physicist, but as far as I can tell, flare is caused by internal reflections within the lens - causing light to fall on the sensor from unwanted directions. Coatings are designed to be specific thicknesses near the wavelength of light that causes destructive interference that eliminates these.
The light reflected by the coating surface and that reflected by the
lens surface have a phase difference of twice the coating thickness.
If the thickness of the coating is one quarter of the wavelength of
the light to be suppressed, light of that wavelength reflected by the
coating surface and light reflected by the lens surface will cancel
each other out. This reduces the overall amount of light reflected. In
short, coatings make use of light wave interference phenomena to
In short, it's likely cheaper lenses/filters have coatings that do not have sufficient tolerances to work effectively at reducing flare.
It might be worth noting that I've only seen flaring this bad on either a very badly smeared lens, a lens with a damaged coating, or a lens with no coating.
Also, any filter will tend to increase flare because the more glass surfaces you add, the more opportunity for internal reflection.