The issue is that epstopdf did not embed needed fonts: Times-Italic and Times-Roman: .
Additional comment: EPS files you provided are ISO 8859-1 encoded, that might be the issue as well.
Can you share the details about your TeX-system, epstopdf version, do you have times package installed etc.?
You probably do not have symbol package installed. Therefore, Symbol font does not get embedded in PDF file, yielding different behavior in various viewers.
How to resolve the issue: install symbol package and try again.
Similar issue: Loss of greek symbols in epstopdf conversion
Check this: https://github.com/MiKTeX/miktex-packaging/issues/112
I had this problem and it turned out the ghostscript bundled with MacTex interfered with the one installed with brew. By looking in the Sublime Text console I could copy the exact ghostscript command being run, then I ran it in a regular terminal and got a better error message: GPL Ghostscript 9.23: Can't find initialization file gs_init.ps. The solution was ...