Scheduled task affecting 0 players

One of our scheduled tasks, that is running on the AllPlayers segment suddenly stopped working properly about a couple weeks ago. When looking at the task history, it shows

Status: succeeded

Players affected: 0

on all past executions.

Additional info:

- The task executes a cloudscript on the AllPlayers segment

- The same cloudscript with the same arguments run manually on an individual player works just fine

- It worked before with the exact same configuration, we didn't change anything

- The AllPlayers segment does show the (almost) correct player count (it is off by about 1k players compared to the count shown on the "Players" tab)

- Example "Summary" from 1 task instance:

{
    "TaskInstanceId": "XXXXXXXXXXXXXXXX-5840",
    "TaskIdentifier": {
        "Name": "MyTask",
        "Id": "XXXXXXXXXXXXXXXX"
    },
    "StartedAt": "2019-11-25T12:00:33.3933508",
    "CompletedAt": "2019-11-25T12:02:06.5980365",
    "Status": "Succeeded",
    "PercentComplete": null,
    "EstimatedSecondsRemaining": null,
    "ScheduledByUserId": null,
    "ErrorMessage": null,
    "ErrorWasFatal": null,
    "TotalPlayersInSegment": 0,
    "TotalPlayersProcessed": 0
}