Restart required after changes in python file

So, I’m not sure if the problem is caused by hydrogen or by atom, the issue is the following:

whenever I do changes in a file that is called by my main file, saving the changed file is not enough. I need to restart atom so that the changes take effect. If I run the program without restarting atom first, it just runs the version prior to the changes. I’m sure there must be some easier path to run the program after making changes to the code.

Any ideas?

I’m using Atom 1.47.0 and Hydrogen 2.14.6 on macOS 11.0.1 (but the same issue already was there on 10.15.x)