Incorrect Formatting of Null Coalescing Assignment (??=) Operator in C# (astyle 3.4)

I encountered an issue with the formatting of the null coalescing assignment (??=) operator in C# code using astyle. Here's the configuration I'm using in astylerc:

--mode=cs
--style=allman
--indent=spaces
--indent-switches
--indent-namespaces
--indent-cases
--indent-preproc-define
--indent-col1-comments
--pad-header
--pad-oper
--pad-comma
--close-templates
--break-blocks
--unpad-paren
--break-one-line-headers
--convert-tabs
--suffix=none
--keep-one-line-blocks
--keep-one-line-statements
--attach-return-type

Given the following code snippet:

public static class Test
{
    private static int? m_value;
    public static int value => m_values ??= GetValue();
    private static GetValue() => 1;
}

Applying astyle changes ??= to ?? =, which leads to a compilation error.I kindly request assistance in resolving this issue or a workaround if available. Thank you!