I had read some articles previously but their links no longer work. The ones below do work.
It wasn't clear to me if this was just rumor; I thought you might have better insight. If you're hearing nothing, perhaps it is only rumor.

Too bad; US might hesitate to put GIs in more aggressively if China was there. But then with Bolton in the game, that might just be further encouragement.

Here are two links and a video:

Chinese Elite Forces to Arrive in Syria (This article is from last November.)

China officially denies sending troops to Syria.