Michigan - July 2023 indictment
Georgia - August 2023 indictment
Nevada - December 2023 indictment
Arizona - April 2024 indictment
Wisconsin - June 2024 indictment
They've all taken a while. It kinda seems like DOJ/Garland didn't pursue this aggressively for fear of being seen as political and states had to figure out jurisdiction issues on what they could do on their own. Michigan even closed their investigation to defer to DOJ I think before reopening.