Hello,
The simplicity of this solution is that the script calculates and saves duration of different packages correctly, see screenshot Screen Shot 2020-10-20 at 3.23.46 PM.png
but displays it incorrectly due to the additional calculation in rlListings.class.php > getMyListings()
this code should be improved in the next update so that it wouldn't affect the "Active Till" date
for now, it's enough to change a piece of code in the .tpl file