Season 1 In 2019, Heart Signal cast member Kang Sung-wook was sentenced to five years in prison for sexually assaulting a woman in August 2017.

[20] Season 2 Heart Signal 2 cast member Kim Hyun-woo was arrested for drunk driving in April 2018 while the show was airing.

[22] While the show was airing, another woman told the media that cast member Kim Kang-yeol had kicked her in the stomach at a nightclub in January 2017.

[23] In May 2023, Yongsan Police Station in Seoul applied for an arrest warrant for Seo Min-jae on charges of violating the Narcotics Control Act.

In September 2022, the police finally collected the hair and urine of Seo Min-jae and Nam Tae-hyun, who were suspected of violating the Narcotics Control Act, and requested an appraisal from the National Institute of Scientific Investigation (NFS).