Bug with a Steam Game; Motorsport Manager, unable to find the source of the bug

this issue is seemingly very complex, I am open to any suggestion. Even from those who have no played the game.

I started playing the game Motorsport Manager from Steam the other week. After completing my first championship I decided to delve into modding. Modding for the game is done via .TxT documents that the game references. I edited the documents and all worked fine, however a few days ago, a game ruining bug started.
The bug causes the AI to never have fuel in their car at race start.
The game is made in unity and coded in C#.
The game hasn’t been updated since 2017.

Currently I have tried;
Reinstalling the game.
Manually replacing the files with files from the base game downloaded to another PC.
Using my account on another PC with cloud sync (Which it worked fine on).
Manually deleting the ‘active mods’ file.
Deleting all cloud sync data.
Resetting my PC to factory settings and reinstalling windows.
I have also verified the files on Steam.

None of these attempts worked. On my PC the game is broken but not on anyone else’s PC.

If anyone has any suggestions I am open to try anything. Thank you in advance.