borders around text when printing

[puregin]

hello

how do i get rid of the borders which appear around certain texts only (see screenshot)? they are only visible on physical print outs (on paper).

printing the same documents with acrobat reader on another computer works fine.
printing the same document on the same computer with e.g. chrome works fine as well.
so i assume this must be caused by a setting in the print process of acrobat reader. i tried to set exactly the same options in the printing process on both machines, but couldn't find out the cause...

both machines run on the same mac os monterey and on the latest adobe reader available.

any ideas?

cheers

puregin