Donald Trump has reportedly lost a key ally in former Fox News CEO Roger Ailes, who decided that advising the GOP presidential nominee was “a waste of time,” according to a Wednesday report.

Ailes and Trump fell out after the former Fox boss learned “that Trump couldn’t focus—surprise, surprise,” New York Magazine editor Gabriel Sherman told attendees at the Vanity Fair New Establishment Summit, according to a report by Vanity Fair. “These debate prep sessions weren’t going anywhere.”

Vanity Fair contributing editor Sarah Ellison reportedly offered an alternate explanation from the perspective of Trump’s campaign, saying that Ailes “kept going off on tangents and talking about his war stories” instead of helping Trump prepare.

In August, the New York Times reported that Ailes was helping Trump with debate prep. Campaign spokeswoman Hope Hicks denied that Ailes was playing any “formal or informal role” in the Trump campaign, saying that Ailes was “not advising Mr. Trump or helping with debate prep.”

According to a report by the Washington Post, Ailes was not involved in preparing Trump for the second debate.

Ailes resigned from his position as Fox News executive after allegations of sexual harassment over the course of his tenure reached critical mass. Trump has faced a recent barrage of similar accusations spanning four decades as numerous women have come forward over the last week with stories of being inappropriately touched by the GOP nominee.