Weird formatting with multiline variable declarations in C++

Version

$ astyle --version
Artistic Style Version 3.3

Example

Input

class A {
    private:
        static float property_a, property_b, property_c;
}

// C++
float A::property_a = 0,
    A::property_b = 0,
    A::property_c = 0;

// C
float A_property_a = 0,
    A_property_b = 0,
    A_property_c = 0;

Expected Output

class A {
    private:
        static float property_a, property_b, property_c;
}

// C++
float A::property_a = 0,
      A::property_b = 0,
      A::property_c = 0;

// C
float A_property_a = 0,
      A_property_b = 0,
      A_property_c = 0;

Actual Output

class A {
    private:
        static float property_a, property_b, property_c;
}

// C++
float A::property_a = 0,
         A::property_b = 0,
            A::property_c = 0;

// C
float A_property_a = 0,
      A_property_b = 0,
      A_property_c = 0;

.astylerc

# Braces
style=attach
attach-namespaces
attach-classes
attach-inlines
attach-extern-c
attach-closing-while

# Indentation
indent=spaces=4
indent-classes
indent-switches
indent-after-parens
indent-preproc-block
indent-preproc-define

# Padding
pad-oper
pad-comma
pad-header
unpad-paren
unpad-brackets
squeeze-ws
align-pointer=name

# Formatting
break-one-line-headers
add-braces
attach-return-type
attach-return-type-decl
convert-tabs
#max-code-length=#

# Other
lineend=linux

Description

I'm not sure if this is intentional, but multi-line C++ (but not plain C) variable declarations are wrapped oddly in my opinion. Thanks!