bad font rendering

[ZPMU]

SumatraPDF version

• Version 3.5.2 64-Bit
• Version 3.2 also affected

Describe the bug
When displaying the given file (SM4007.pdf, see link below), there are many letters that don't show up in SumatraPDF, but do (and looks sensible) in PDF-XChange.

To Reproduce
Steps to reproduce the behavior:

1. Open SM4007.pdf
2. Compare view with output of PDFXChange

Expected behavior
I expect that this file will be displayed as intended or a sensible error/warning message about a faulty file be displayed

File that reproduces the problem
https://www.semikronsemi.com/datasheet/semikronsemi/SM4007.pdf

Screenshots

Additional context
Don't know if this is an issue with SumatraPDF or with the PDF file.

[GitHubRulesOK]

Problem file so it does not get reported as problems nor fixed as it uses Type1 definitions (Helvetica Font to be substituted by Printer Hardware) change the names to Windows (Arial) and resave and it works.
SM4007A.pdf

GhostScript will correct it with universal nimbus (throws me an error but finishes the correction)

sm4007-GS.pdf
OK my bad command line it should be fixed using just this (mine is ...32c.exe)

gswin32c -sDEVICE=pdfwrite -o"%cd%\SM4007-GS.pdf" -f "%cd%\SM4007.pdf"

Processing pages 1 through 2.
Page 1
Loading font Helvetica-Bold (or substitute) from %rom%Resource/Font/NimbusSans-Bold
Loading font Helvetica (or substitute) from %rom%Resource/Font/NimbusSans-Regular
Page 2

[kjk]

Happens in pre-release and mupdf-gl

For the archives, the repro file:
SM4007A.pdf

This file uses non-embedded Helvetica-bold font and one embedded font.

Not sure which one is a problem.