I'm using TeX Live 2019 with LaTeX compiler (in Overleaf). I have the following code:
\documentclass[border=2mm]{standalone}
\usepackage[many]{tcolorbox}
\begin{document}
\tcbox[enhanced,drop fuzzy shadow ]
{This is a tcolorbox.}
\end{document}
but I obtained
By using pdfLaTeX compilation with TeX Live 2019 or LaTeX compilation with Tex Live 2017, I obtain the right result:
What could be the problem? How can I fix it?