Problems when convert PDF to png some characteres are converted on black boxes

[cyberfido]

ImageMagick version

6.9.12-32

Operating system

Linux

Operating system, version and so on

Ubuntu 20.04

Description

I'm running this command
convert -define bmp:format=bmp3 fail_symbol.pdf test.png
then I added a -verbose to get the information on what is imagemagick sending to ghostscript, and this is the result command:

gs -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 '-sDEVICE=pngalpha' -dTextAlphaBits=4 -dGraphicsAlphaBits=4 '-r72x72' -dPrinted=false -sOutputFile=test.png fail_symbol.pdf

if I execute that, I got a incorrect output:

with some characters like a blackbox, then if I drop the value -dPrinted=false from the script I got the correct results, now my question is how can I configure imagemagick delegates or which parameter do I have to send to ghostscript to avoid -dPrinted=false on the script

Steps to Reproduce

run the command

convert -define bmp:format=bmp3 fail_symbol.pdf test.png

with the PDF Attached

Images

fail_symbol.pdf