Having trade relations does not mean China supports a country. US has always been China’s largest trading partner, but China <-> US relations can hardly be called "friendly".

The CCP government has absolute control over domestic public opinion. The pro-Russia direction on Chinese social media is very clear, although as the war became unfavorable for Putin, voices supporting Ukraine have been allowed a little more in recent years.

What the US supports is what China opposes. From Iran to Venezuela, from Gaza to Ukraine, except for a very small amount of "human consensus", it is always and will be like this.