There seems to be bug with the JSON Editor for viewing readonly player data.
E.g. I have a key-value pair whose value string looks like this
{"submissionId":637274825800463160,"leaderboardName":"Tournament","score":1,"when":"2020-06-11T14:29:41.6509044Z"}
However, when viewing in the JSON Editor I see this
{ "submissionId": 637274825800463100, "leaderboardName": "Tournament", "score": 1, "when": "2020-06-11T14:29:41.6509044Z" }
Notice the difference in the submissionId field.