This is not an obvious example of 50 cent army; in fact you're unlikely to find anything that you can incontrovertibly call the CCP. This was an example of Chinese nationalism in general. I watch a ton of US China trade war stuff, the closest thing I could give you to an example of what legitimately appears to be a state actor was triggered by something like this: 'yeah China might be good but gdp per capita america = 60k gdp per capita china = 9k'

Followed by an 8 paragraph monologue about American imperialism, the prison industry, etc.

Of course this isn't verifiable, and maybe you're right, perhaps it is just one angry guy in China. I do not really care who it is, I am just trying to point out how we're quick to flip out about Facebook ads bought in Rubles, yet when it comes to Chinese troll artistry we are completely silent meanwhile Russia is a declining power and China is a mercantilist adversary.