On December 19, Starship Entertainment updated fans after all members of MONSTA X took part in voluntary COVID19 testing. 

The label stated, 

"We notify you regarding MONSTA X's COVID19 test results. As a staff member from the set of 'The Masked Singer' tested positive for COVID19 around the time that MONSTA X's Minhyuk and Kihyun took part in the program's recording, all of MONSTA X as well as their affiliated staff underwent precautionary testing. According to the results provided by a testing center in Seoul, all members of MONSTA X have tested negative, while remaining staff members are still awaiting their results. We apologize for causing many fans concerns, and we will continue to do our best to abide by COVID19 prevention measures. Thank you."

Meanwhile, a total of 6 weekend programs will not be airing on MBC due to recently discovered staff cases of COVID19.