Didn't see it myself but my mate in Rugeley has family over in Wisconsin and they were going on about something similar a few weeks back, triangular, silent, slow moving. Thing is I cant find the original thread where someone posted dashcam footage - does anyone have a link to that? Pretty sure it was on here maybe 2-3 months ago.
Also what time roughly did you see it Thursday? Trying to work out if theres a pattern with the sightings because I've been tracking a few of these triangle reports across the midwest and the timing keeps coming up between 9pm and midnight local time. Could be nothing but could be something worth mapping out properly.