Only months after a data-privacy scandal, Facebook is seeing fewer frequent users than it expected.

The social-media company reported 2.23 billion monthly active users, just shy of Wall Street forecasts of 2.25 billion. Its total user count represents an 11 percent increase over the year-ago period.

While it was the company’s first full quarter following the Cambridge Analytica privacy scandal, analysts attributed the user-growth shortfall largely to European privacy rules that went into effect in May.

It’s the first time Facebook whiffed on an earnings forecast since 2015. It’s been a volatile day for the company’s stock, which reached a record high Wednesday morning before the earnings report came out.

Facebook shares sank more than 20 percent, to $173, in after-hours trading. One factor that may be spooking investors: Facebook’s slowing revenue growth as the company moves to restrict how members’ data is used.

“We expect revenue growth rates to continue to decelerate in the second half,” Facebook Chief Financial Officer David Wehner said in a conference call with analysts to discuss the latest results. “In addition, we’re continuing to focus our product development around putting privacy first, and that’s going to, we believe, have some impact on revenue growth,” he added.

Facebook’s focus on promoting new services, such as Stories, is also coming at the expense of revenue growth, Wehner said.

In the second quarter the Menlo Park, California-based company posted revenue of $13.2 billion in the period, up 42 percent from the year-ago period but still short of Wall Street estimates. Fourteen analysts surveyed by Zacks Investment Research expected $13.4 billion. The company earned $5.1 billion, or $1.74 per share, for the quarter.

Advertising revenue for the quarter was $13.04 billion, missing analyst forecasts of $13.16 billion.

Facebook has largely saturated the U.S. and Western European markets, and is now looking to countries such as Brazil, India and Indonesia for new users. Revenue from these regions, however, is far below what Facebook rakes in from the U.S. and Europe.

Analysts are watching to see how Facebook recovers from the privacy scandal involving Cambridge Analytica, a data firm that improperly accessed information from as many as 87 million Facebook users.

Despite the focus on Facebook’s role in the affair, its shares have increased 23 percent since the beginning of the year, compared with a 6.5 percent rise for the Standard & Poor’s 500 index. In the final minutes of U.S. trading on Wednesday, shares hit $217.50, an increase of 32 percent in the last 12 months, before sinking after the bell.

Daniel Ives, head of technology research at GBH Insights, said in a note that investors “clearly viewed Cambridge as a ‘blip on the radar,’ although some soft spots in the advertising and overall user metrics will fuel the debate about further bumps in the road” for Facebook.

“The fundamental damage to the Facebook platform has been ‘very contained’ in our opinion and is generally better than feared from the white-knuckle period a few months ago,” he added.

One area of Facebook’s business showing robust growth: Instagram, which now has more than 1 billion active users using the photo- and video-sharing platform.

“We believe Instagram has been able to use Facebook’s infrastructure to grow more than twice as quickly as it would have on its own,” Facebook co-founder and CEO Mark Zuckerberg said in the call.