Created attachment 839090 [details]
CUPS error log

CUPS version 2+ along with OpenSUSE 15+ prints only 1 copy of a postscript file
instead of multiple. 

Content of a postscript file:

%%EndProlog
%%BeginSetup
<< /PageSize [590.625 835.3125] /ImagingBBox null /ManualFeed false /NumCopies
2 >> setpagedevice.
%%EndSetup
%%Page: 1 1
/pgSave save def
835.3125 0 exch translate 1 -1 scale[72 300 div 0 0 72 300 div 0 0]concat

This is from CUPS error_log

d [24/Jun/2020:15:17:29 +0200] cupsdProcessIPPRequest: copies integer '1'

You can clearly see the parameter "/NumCopies 2" but when the file gets
processed there is a mention in error_log "copies integer '1'.

It works perfectly fine on older distributions and older CUPS versions.