There are numerous reports from Maricopa county, Arizona, that people were given sharpies (by pollers) to fill their ballots, and subsequently those ballots were presumably invalidated because they were not filled with a ballpoint pen - hence unrecognizable by the machine.

On Crowder YT feed they said additional reports about similar actions (sharpies given by pollers) in Livonia and Macomb counties, Michigan. His team is asking everyone to report to them about other locations (eventually with pics/videos) where this might also happened. Seems like a premeditated concerted action across states. Contact them at @scrowder with State, County, polling station