VBA Log function Runtime Error '5': Invalid procedure call or argument

I am trying to use the VBA Log function in an expression and I expect it to work on any number greater than 0. However, when I enter a relatively large number (e.g. 500 or 1,000), I get the error mentioned in the title. Here is the function:

Function f_x(x As Double) As Double

    f_x = 5 - x - Log(x)

End Function

I am using Option Explicit and I get the error when I enter x as any number greater than about 500.

Maybe it has something to do with the sub I'm using the function in then? It gives the error if x is anything above exactly 403 (after further testing) and when I click "Debug" It highlights the line where I defined f_x.

Full code:

Option Explicit

Function f_x(x As Double) As Double
    
    f_x = 5 - x - Log(x)

End Function

Function f_prime(x As Double) As Double

    f_prime = (-1) - (1 / x)

End Function

Sub Newton_Method()

    Dim guess As Double
    Dim tolerance As Double
    Dim next_guess As Double
    Dim iterations As Integer
    
    
    iterations = 1
    guess = Range("B1").Value
    tolerance = Range("B2").Value
    
    next_guess = guess - (f_x(guess) / f_prime(guess))
    
    Do Until (Application.WorksheetFunction.RoundDown(guess, tolerance) = Application.WorksheetFunction.RoundDown(next_guess, tolerance)) Or iterations = 100
    
        guess = next_guess
        next_guess = guess - (f_x(guess) / f_prime(guess))
        iterations = iterations + 1
    
    Loop
    
    Range("B4").Value = next_guess
    Range("B5").Value = iterations

End Sub