Russia and China don’t march in lockstep, and Russia’s announced conditions for a ceasefire are considerably more stringent than China’s proposal. From Andrew Korybko at korybko.substack.com:

Without some irreversible moves first being made on Kiev’s part, it’s unlikely that Putin will agree to China’s latest call for a prompt ceasefire, so Xi and Orban should now concentrate their joint efforts on convincing Zelensky to carry out his own “goodwill gesture” in order to help bring this about.
Chinese President Xi Jinping reiterated his call for a prompt ceasefire during surprise talks with Hungarian Prime Minister Viktor Orban in Beijing on Monday, declaring that “A prompt ceasefire and hostilities [in Ukraine], as well as the search for a political solution, meets the interests of all parties.” The two leaders also confirmed that their positions towards this conflict coincide and asked the rest of the international community to do whatever they can to restore a direct Russian-Ukrainian dialogue.
For as noble it may be, Russia is unlikely to heed this latest call since Putin already told Orban during their meeting on Friday that he’s not optimistic about implementing a ceasefire before the resumptions of talks with Ukraine since he suspects that Kiev would exploit it to rearm. Furthermore, the Russian leader already shared his own ceasefire proposal in mid-June, which demanded that Ukraine withdraw from the entirety of Russia’s new regions as a precondition for peace.
Agreeing to a prompt ceasefire that leaves Russian-claimed territory under Ukrainian control could lead to accusations that Putin is contradicting the constitution after one of the amendments from 2020’s referendum prohibited ceding any of the country’s territory. Nevertheless, a legal loophole could be that nothing is being formally ceded even if the state of affairs remains in place indefinitely, plus the Ukrainian-controlled areas never voted in September 2022’s referendum to unite with Russia.