Lister was diagnosed with COVID-19 around August 2020, and overcame the illness. He became ill with symptoms similar to COVID-19 a second time in early December, such as weakness and trouble breathing, which forced him to cancel shooting for a film. His manager Cindy McGowen, who said it was not normal for him to miss filmings, became concerned and sent her assistant to his house to give him vitamins and antibiotics. He also canceled a Zoom appearance at a TV festival.