The UK's No. 1

This question refers (of course) to the act that had the Christmas No. 1 in the UK in those three years. But it's already out of date; because LadBaby had the Christmas No. 1 in 2021 as well.

As we were reminded last week (Week 7, 1 February – General Knowledge, Question 14) which referred to the fourth consecutive Christmas No. 1 for Ladbaby (a.k.a. Mark Hoyle).