WASHINGTON — One year after President Trump fired the F.B.I. director, James B. Comey, agents say they have less confidence in the ethics and vision of the bureau’s new leadership, according to internal survey data.

The survey results further undercut one of the explanations that President Trump and his aides gave for firing Mr. Comey and replacing him with Christopher A. Wray. Mr. Trump said the bureau was in turmoil and agents had lost confidence in Mr. Comey.

The internal data suggest that Mr. Trump either misread those views or mischaracterized them.

As a whole, morale at the F.B.I. remains high, despite a barrage of attacks by the president and his allies. Agents said they are proud to work at the F.B.I., believe in the mission, look forward to going to work and believe their job makes a difference. Scores in those areas remained steady.

By themselves, the numbers do not explain the decline in leadership scores. Mr. Wray was largely unknown to most agents when he came into office during one of the most tumultuous times in F.B.I. history. He brought with him a fresh leadership team and a more low-key style than his predecessor. He has also opted not to spar publicly with Mr. Trump, even as the president has attacked the bureau and accused agents of being part of a “witch hunt” against him.