Former NFL player Sergio Brown is being held at the Cook County Jail as he awaits trial on a first-degree murder charge for the death of his mother, Myrtle Simmons-Brown, and RadarOnline.com has learned he’s faced no disciplinary action while in custody. Brown was booked in Oct. 2023 after being charged with first-degree murder and concealment of the body of 73-year-old Simmons-Brown, for which he pleaded not guilty. A visitor log obtained by RadarOnline.com showed that he’s been visited 18 times by nine different people since the date he was booked. The 35-year-old had traveled to Cancún befo…