Fox News is having trouble keeping its advertisers happy.

Ad revenues plunged 17 percent in September over the same month last year, according to the most recent financial data for the operation.

Statistics from the Standard Media Index, which tracks media income, showed that Fox News took the biggest hit of any cable news operation. CNN, which President Donald Trump frequently describes as “fake news,” lost just 1 percent in revenue, and MSNBC was up 2 percent.

Cable news revenue was down an average of 7 percent for the entire third quarter (July, August, September) over the same period last year, Ad Week reported.

Costs for 30-second advertising spots rose in September over the same month last year for MSNBC’s “Rachel Maddow Show” (up from $3,800 to $4,600), “The Last Word with Lawrence O’Donnell” (up from $3,100 to $3,700) and “All In With Chris Hayes” (from $2,700 to $3,300).

Advertisers were still spending the most for 30-second spots for Fox News personalities, even though costs were down significantly. A 30-second spot this September cost $12,200 for “Tucker Carlsen Tonight,” and $8,500 for Sean Hannity’s program. Last year, during the election, spots on Fox News were going for as much as $31,300.

Several advertisers left Hannity’s program this year after he pressed a discredited conspiracy theory about Democratic National Committee worker Seth Rich, who was killed in a robbery. Even though the network issued a retraction, Hannity continued to link Rich’s slaying to WikiLeaks. A Stop Hannity effort succeeded in persuading a number of advertisers to quit the program, Media Matters reported.

There was no immediate word from Fox about the change in the channel’s fortunes.

Video: Hannity says he'll be at @FoxNews "as long as they want me," denounces efforts to remove him, and promises search for "the truth" pic.twitter.com/SHRMsLHBiF — Curtis Houck (@CurtisHouck) May 24, 2017