However, the Conundrum still features a mechanical set rather than the digital one used on the normal, afternoon episodes since mid-August 2020. Cosmetic changes include all four players competing in Rounds 3 and 4 rather than taking turns to face off a player from the opposing team and the outro's tune was changed to the show's theme tune. This included the absence of a studio audience, the installation of a plexiglass in Dictionary Corner, social distancing being enforced where each player sat two metres apart from each other and having their own buzzer instead of one per team for the Conundrum. The Christmas special and first three regular episodes of the series were recorded prior to the pandemic, following which, many changes were enacted in order to comply with COVID-19 guidelines.

Recording resumed in December 2020 when Rachel Riley announced it on her Twitter feed. 8 Out of 10 Cats Does Countdown Series 21 was a series of seven special episodes of 8 Out of 10 Cats Does Countdown that began on 21 December 2020 with a Christmas special and ended on 18 February 2021.