Python program/controller works for one user but not others

I am way out of my depth with this one, but please hear me out and help me improve this question.

There is a program built in Python with a GUI that I use at work for web scraping. The program (the person who built it used to call it a controller) takes an excel file with a list of URLs and scrapes a specific page element from each URL. Then in the same excel file, it spits out the scraped data in a new column. The .exe file along with all the necessary packages and dependencies are located in a shared network folder on a remote desktop. So is the excel file. This means everyone in the team will be using the same program and data file.

The problem is- every time I run the program, it scrapes a few URLs and get stuck at some random URL, but when my colleague runs it, it works without a problem. There is no error message or anything, it just gets stuck for hours. Web scraping is just one of the things you can do using this controller. It's mostly used for submitting scripts and those work just fine.

So what I am looking for is some kind of "Here's what/where you should look into!" comments/answers. Anything that will lead me to the right direction towards solving this would be huge.