Concentric circles in long exposure photos of Northern lights

Using an iPhone 15 pro max in night mode and tripod, whenever I set it for a longer exposure there would be a set of concentric circles in the photo. It seems most pronounced with longer exposures (more than the auto setting) and rarely appears with shorter (less than 5 second) exposures. I have not noticed this with any other night mode photos, even a sky with stars, just when photographing the northern lights. The Genius Bar analytics said the physical camera was operating properly and that maybe it was a software issue - but testing that theory would require whipping my phone and NOT restoring from backup - yikes! Has anyone else encountered this or found a solution? Thankfully Lightroom helped me salvage some of the photos with editing, but I would sure like to not have to edit myself out of this issue.