I am compiling a simple Beamer document in two almost identical Linux boxes (Manjaro KDE 2017.3). They both have the same full TeXLive 2017 installation, properly updated. (They have the very same programmes installed, but they have somewhat different hardware: on has an Intel 430 graphics card, while the other has a Radeon card.)
The MWE is as follows:
\documentclass{beamer}
\usetheme{Madrid}
\begin{document}
\begin{frame}
\titlepage
\end{frame}
\end{document}
However, one of the computers produces a wrongly rendered shadows, as you can see here:
while the other does it correctly:
Notice that it is not a problem of the PDF application I'm using, since the bad PDF output is displayed badly in both PCs.
Any ideas as to what can be occurring here?