I dunno, they didn't blame or sanction Belarus for the talks breaking down and Belarus is an outright Russian core ally.China should absolutely not mediate a ceasefire or host talks.
In the end, either Russia or Ukraine is going to be humiliated. Most likely Ukraine.
If Russia is humiliated, you betray your strongest ally. An ally with massive nukes, the #2/#3 army in the world, and a long northern border. The ally that will supply food, oil, and natural resources in any future war with America.
If Ukraine is predictably humiliated, the EU will blame you for Ukraine's defeat. You are now an accomplice to Russia and the European peoples will find a true reason to genuinely hate China. The EU still hasn't put broad tariffs or sanctions on China.
Let's keep it that way. Avoid this poisoned chalice.
Then again they are also looking for an excuse to take down China. Hmm.
I admit that forcing Ukraine to sign an unequal treaty could look bad. Might not be a good idea after all.