VRChat | VRChat source code for MHack | Augmented Reality library

I seen similar posts but nothing was really close to how I'm doing things so I made another post. I'm building a scoreboard for a map I'm making in VRChat and in case someone is not familiar with how that goes, VRChat limits what people can do with C# so I can't use lists, dictionaries, or do convenient things like import the System library and use Array.Sort() or Array.Reverse() and so on.

I used my own sorting method to get an array of player scores in descending order but the original index positions of the scores is important to keep consistent with the array of players ID's. So I need to know where the current score index was in relation to where it is after being sorted. for example {10, 20, 30, 40, 15} would be sorted {40, 30, 20, 15, 10} and I need reference to where the original order of scores are now in the sorted array, so I would make a indexSorted array that I need to give me back {3, 2, 1, 4, 0}

I'm now working on the nested for loop to get that data for me. So I keep the original array and make a copy so that I can compare array elements against each other to get the data. It seems to be working for the most part but I'm having a slight issue. The following code uses test data so I can get the algorithm working first before I implement it into my map and for the convenience of replicating my code and trying to help me figure out what's going wrong.

Output of indexSorted array: {4, 3, 1, 2, -1, 5} -1 indicates there was an issue in the loop but the logic seems to make sense to me so I can't figure out what it's doing wrong. indexSorted keeps track of index's already checked so I don't want to populate the array with any positive integer or 0