"China can not afford to have Russia fail in Ukraine. If a settlement is not reached that gives Russia some territory in Donbas and Luhansk and allows it to keep Crimea, this war will drag on and China will first covertly and then, depending on the future of the hostilities, openly support Russia."

https://medium.com/politically-speaking/why-taiwans-fate-is-tied-to-ukraine-s-9f5c2f3b52be