Unreproducible pythonnet install #1696

Environment

• Pythonnet version: 2.5.2
• Python version: 3.8.12
• Operating System: Windows 10
• .NET Runtime: 4.8

Details

I'm trying to implement someone else's code which makes use of external DLLs. It is my first time using pythonnet.
The code is as follows :

import clr
dll_path = r'C:\Users\<user>\Documents\external\Tp.IO.dll'
clr.AddReference(dll_path)

Which generates the following error :

Exception has occurred: FileNotFoundException
Unable to find assembly 'C:\Users\<user>\Documents\external\Tp.IO.dll'.
   at Python.Runtime.CLRModule.AddReference(String name)

I've browsed the issues of this repo, and this is apparently fairly common, so I tried to solve the issue myself.
While messing around with conda and pip installs, I accidentally installed the clr package through pypi and then uninstalled it, which somehow solved the problem. One further detail is that the clr of the import clr line was now displayed in green in VS Code, which is the case for packages successfully found in the conda environment used.

However, as I tried to make the code work on another, similar computer, I faced the same problem as before, but I was unable to reproduce a working install of pythonnet.
This computer is the running the same version of Windows, .NET, and as a conda environment with the same version of Python and Pythonnet.
I've tried replicating the steps I've used before, exporting the original conda environment as a YAML file and importing it to the other machine, copying the pythonnet folder found in site-packages, even copying the entire environment itself, to no avail. And, as an indicator, import clr still has clr in white in VS Code, which leads me to believe something isn't working properly with the installation process.