I just tried and I have good results with the odt plugin
https://www.dokuwiki.org/plugin:odt .
pdf created by this plugin have the arrows.
Unfortunately, there are other issues. schemas that are too wide are not correctly resized
and are cropped. This may be an a2s bug or a odt pluglin issue. Right now, I don't have
time to investigate (or fix).
If you can install libreoffice on your server, that may be a solution to your problem.