Hi,
I don't have PHP 7.2. but 2017-12-26 just work fine with PHP7.0 and DW Greebo. Here's what you can try :
1) revert to 2017-12-26. 2005-07-22 is just too old.
2) try this in your page
<phpwikify>
echo " * this is a list\n * second item";
</phpwikify>
If it works, check your inner PHP, the problem could be there.