China is buying more debt, it is just the debt has massively increased.
Discussion
βChina has significantly reduced its holdings of U.S. Treasuries in recent years. At the end of December 2024, its portfolio stood at $759 billion, the lowest since February 2009. This represents a decline of approximately $557 billion from the all-time high of more than $1.31 trillion reached in November 2013. β
I understand they have been buying through intermediaries such as the UK. That's why the UK number looks higher but it's really China.