Checked the South China Morning Post (Hong Kong) in re: Trump/Tsai call. It usually reports on the official Beijing response, but this article says there has been none so far.

scmp.com

I have this image in my mind of a roomful of irate, confused foreign policy ministers in Beijing revising over and over the government’s official response to Trump’s call. They’re used to dealing with professionals, not a loose cannon rolling around wildly on a pitching deck.

I anticipate an official Beijing response by this afternoon, Beijing time. No way will they let this insult pass without a stern response.