Keeping a persistant score variable between play sessions - weird bug?

We are making a basic atari remake for a university assignment, and have hit that road block where the world collapses in on itself. One of the problems were having baffles us completely.

The score value is not behaving properly. If the player collects points, and we end the play session, when we start a new play session, the score stays at the new value (say, 200). You can pick up the first pick up and hit 400, hit stop, hit start to begin a brand new play session, and start with the score of 600. You can continue to build the score this way. There is a start command set to make score = 0.

how is this even possible?

We never did truly fix this bug; though we found the source of a lot of “weird behaviors” that could point to why this was happening.

Our teacher directed us in creating the ignore file for Git, and in doing so, gave us incorrect information in regards to ignoring the library folder. As a result, our project contained bits and pieces from everybodys library, including meta data from much earlier builds.

It is worth establishing that we never implemented persistent data; the problem could not have been our use of the PlayerPrefs file, because we simply did not use a PlayerPrefs file. If this sort of thing ever comes up for future users, I would simply recommend deleting your library folder, and restarting Unity.