The Chinese (and very few westerners TBH) don't understand the "she's, strictly speaking, operating under her role in the Legislative Branch (we had a few visits by Senators while I was deployed some years ago, something similar) and not beholden to the Executive Branch for permission."
They're a dictatorship - and everything flows from the top - they think we're taking them for fools by saying that she might not have approval from Biden to go