One of China’s most influential, and garrulous, nationalist voices on social media has suddenly gone quiet, and the country’s internet is wondering why.

Hu Xijin, the former editor of the Global Times, a pugnacious Communist Party-run newspaper, writes and posts videos regularly on Sina Weibo, a social media platform, where he has nearly 25 million followers. But in late July, Mr. Hu stopped updating his page, baffling readers and gratifying some of his critics.

Mr. Hu has not explained his silence; nor have China’s internet authorities. But many in China think he has been censored, pointing to signs that party officials may have been irked — paradoxically — because Mr. Hu lauded them in the wrong way. In China, even misplaced praise for the party may be enough to draw the ire of censors.

A possible source of Mr. Hu’s trouble appears to be a Weibo post he wrote in July that extolled as “historic” the outcome of a party leaders’ meeting on economic strategy. In Mr. Hu’s view, the party used phrasing in its plan for the economy that suggested that China would reduce the status of state-owned companies, giving private companies a big boost.

The plan opened the way to “true equality” for private and state companies, Mr. Hu wrote to his millions of readers. “Not so long ago, some people were openly denigrating the private sector,” he wrote. “How ridiculous those voices seem today.”

Mr. Hu’s post soon disappeared from Weibo, but not before it set off a kerfuffle.

Mr. Hu’s praise may have seemed helpful to policymakers at a time when the Chinese government is desperate to restore the confidence of private businesses, which generate vital jobs and tax revenues. But he was assailed by hard-left critics who accused him of distorting the party’s words and undermining China’s commitment to state companies. “This blows open his fundamentally anti-party, anti-socialist thinking,” read a comment republished on Utopia, a far-left Chinese website.

The New York Times