In-text disambiguation of first authors using initials sometimes uses non-first authors

[xwhatsit]

This occurs with both biblatex-apa v8.0 (APA 6 style) and v9.6 (APA 7 style).

The in-text disambiguation of first authors (using initials) works as expected, aside from the fact it also looks at second (and third etc.) sometimes.

Example:

@article{bloggsAndSmith2001,
    title = {Title 1},
    author = {Bloggs, Joe and Smith, John},
    date = {2001},
}

@article{smith2002,
    title = {Title 2},
    author = {Smith, Adam},
    date = {2002},
}

@article{smith2003,
    title = {Title 3},
    author = {Smith, Adam},
    date = {2003},
}

\documentclass{article}
\usepackage[style=apa]{biblatex}
\addbibresource{bib.bib}

\begin{document}

\cite{bloggsAndSmith2001}

\cite{smith2002}

\cite{smith2003}

\printbibliography
\end{document}

This produces:

Bloggs and Smith, 2001 A. Smith, 2002 A. Smith, 2003

References Bloggs, J., & Smith, J. (2001). Title 1. Smith, A. (2002). Title 2. Smith, A. (2003). Title 3.

As far as I can understand, A. Smith should not need the initials added to the in-text citation.

Interestingly, removing one of the references (any of them, for all other permutations) produces expected results, e.g.:

\documentclass{article}
\usepackage[style=apa]{biblatex}
\addbibresource{bib.bib}

\begin{document}

\cite{bloggsAndSmith2001}

\cite{smith2002}

\printbibliography
\end{document}

Bloggs and Smith, 2001 Smith, 2002

References Bloggs, J., & Smith, J. (2001). Title 1. Smith, A. (2002). Title 2.

or:

\documentclass{article}
\usepackage[style=apa]{biblatex}
\addbibresource{bib.bib}

\begin{document}

\cite{smith2002}

\cite{smith2003}

\printbibliography
\end{document}

Smith, 2002 Smith, 2003

References Smith, A. (2002). Title 2. Smith, A. (2003). Title 3.

[plk]

This was actually a fairly obscure biber bug which has been corrected version 2.15 DEV on Sourceforge.

[xwhatsit]

The development biber version indeed fixes the issue for this 600+ item reference list. Thank-you so much!