[Tex/LaTex] Beamer title page extra line space in author

beamertitles

getting some extra line space between Prof. DEF GHI and Prof. Jklmno Pqrst in the following beamer latex code. How to solve it?

\documentclass[mathserif,10pt,graphics]{beamer}

\title[Title]{Title}
\subtitle{\vspace*{0.5cm}{Subtitle}}
\author[ABC]{ABC\\[5mm]{\footnotesize \textbf{Supervisors:}\\Prof. QWERTY\\Prof. DEF GHI\\Prof. Jklmno Pqrst}}
\institute[UniversityXYZ]{}
\date[Today]{Today's date}


\begin{document}

\begin{frame}
    \titlepage
\end{frame}
\end{document}

enter image description here

Best Answer

I have no idea why, but if you add \\ to the end of the last professor it fixes the problem.

\author[ABC]{ABC\\[5mm]{\footnotesize \textbf{Supervisors:}\\Prof. QWERTY\\Prof. DEF GHI\\Prof. Jklmno Pqrst\\}}