If you submit an array (empty or filled) as the payload to /1/submit-listens

E.g. this request:

POST /1/submit-listens HTTP/2
Authorization: Token ***
Content-Type: application/json
[]

Result:

HTTP/2 500 Internal Server Error
{"code":500,"error":"An unknown error occured."}

If you instead submit as body some other JSON that is not a valid request, e.g. {}, then it gives the below result:

HTTP/2 400 Bad Request
{"code":400,"error":"Invalid JSON document submitted."}

This is also what I would expect for the empty array request.