The lens on the 11 *is* either scratched or dirty. Since you say the lens was cleaned, it's most likely scratched internally. What you see in the last photo in the comparison is not a 'lens flare', it looks like a
diffraction spike (the light lines go through every point light source, while a lens flare, which is caused by internal reflection of the lens, doesn't have to go trough the point light sources, and certainly not through all of them, like in the iPhone 13 photo, which does look like a lens flare) .
Usually, since a phone has a fixed (round) aperture, the diffraction spikes should have no particular shape (diffracting equally in all directions), while in DSLRs with lenses with straight-bladed apertures, the diffraction spikes do take specific patterns. A single diffraction spike in one direction points to oils on the lens (fingerprints, etc, which are usually wiped in a single direction, causing the diffraction spike to be mostly in one direction) or by a scratch on the lens. Since the diffraction spike is slightly curved, I'd bet on a scratch on one of the internal surfaces of the lens (which are curved).
Or maybe I'm totally wrong, idk. It's late.
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