When including certain PDF files as graphics, some greek symbols are not present during the preview. This was however not the case with the previous build of TexStudio (v.3.5), only noticing this with the latest release.

Environment

• TeXstudio: 4.0.0
• Qt: 6.1.3
• OS: Windows 10
• TeX distribution: miktex

Expected behavior

All the greek symbols should be present:

Actual behavior

How to reproduce

Attaching the original file that is causing the issue for me. Other PDF readers in my machine show all the symbols without issues.
missing_title.pdf

The attached file was generated using R with the following code:

require(latex2exp)
require(ggplot2)
p <- ggplot(diamonds, aes(x=carat, y=price, color=cut)) + ggtitle(TeX(r'($\rho = 1, \sigma = 2, \epsilon = 2$)'))
pdf(file='missing_title.pdf')
print(p)
dev.off()

And included into latex straightforwardly:

\begin{figure}
	\includegraphics[width=1\linewidth]{missing_title.pdf}
\end{figure}