White House aides have reportedly claimed that President Joe Biden is only “dependably engaged” during a six-hour window span.

Several White House aides have reportedly “seen flashes of an absent-minded Biden” during certain instances, while also seeing Biden appear “engaged” during other instances, eight current and former White House aides reportedly told Axios.

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Sources told the outlet that Biden is reportedly “dependably engaged” between the hours of “10am to 4pm.”

The sources added that “outside of that time range” or even when Biden is traveling abroad, “verbal miscues” and fatigue are more likely to occur.

This comes after Biden appeared to freeze and looked confused during the presidential debate, which began at 9:00 p.m. Eastern on Thursday against former President Donald Trump.

Biden also spoke with a hoarse voice, mumbled, and repeated debunked claims like the “very fine people” hoax and the “suckers and losers” false claim.

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The 81-year-old president’s debate performance has raised doubts about whether he is mentally and physically capable of serving another term as president, with several people suggesting that Biden be replaced.

Several donors have also been sent into panic mode after seeing Biden’s poor debate performance and have called for him to drop out, while others have reportedly backed away from Biden.

Despite these concerns, the Biden campaign has maintained that Biden is “not dropping out” of the presidential race. Former President Barack Obama and former President Bill Clinton issued statements of support after Biden’s performance at the presidential debate.

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The Biden campaign also rolled out a fundraising email with a message from actor Robert De Niro, who has been a vocal supporter of Biden.

The day after the presidential debate, Biden spoke at a rally in North Carolina where he appeared fiery and more energetic.

During the rally in North Carolina, Biden admitted that he does not “walk as easy,” “speak as smoothly,” or “debate as well” as he used to.

A Rasmussen Reports poll conducted between May 28-30, found that 57 percent of voters feel that Biden has gotten “less and less mentally sharp” over time, while 34 percent disagreed.

In an NBC News poll conducted between January 26-30, 62 percent of registered voters have “major concerns” that Biden lacks the mental and physical health needed to serve a second term. Fourteen percent expressed having “moderate” concerns, while 13 percent said they had “minor concerns.”