Still, I think it's either a bug with preflight or at least an unexpected behavior of the preflight function.
Preflight had an error with the first insertion point after the auto bullet; not with a specific character.
At least it says that the error is related to the bullet, but it is showing an insertion point only when I click to select the error on the page.

FWIW: At least the individual information on the shown error is highly misleading.

Problem is described here and ID sample with the problem available at this address: https://community.adobe.com/t5/indesign-discussions/new-problem-with-non-proportional-scaling/m-p/12903503#M474837