Relative path problem in Perl

I have a software for about 4 years which recently a user reported that he was having issues with the relative path. The main script that he has the issue is this file. I suspect that the problem lies at these lines.

In response, I proposed using the FindBin module modifying it to this instead. This would ensure that no matter from where he runs the main script, the relative paths would be fixed to the position of the running script but not cwd. (Here is a video I did for him in response)

However this has not solved his issues. Any body else is having any idea?