I have an aggregate query, when the character in pipeline over 21066 character, the result return wrong format that the pipeline expected. So I wonder is there any limitation on size of query in pipeline?

My case is:
Query: [
"$match":{"profileID": {"$in": ['', .....]}},
{"$group":{"_id":"$profileID","materialLevel2":{"$sum":{"$cond":[{"$and":[{"$eq":["$expenseL2","true"]},{"$eq":["$expenseL3","false"]},{"$eq":["$expenseL4","false"]}]},1,0]}},"materialLevel3":{"$sum":{"$cond":[{"$and":[{"$eq":["$expenseL3","true"]},{"$eq":["$expenseL4","false"]}]},1,0]}},"materialLevel4":{"$sum":{"$cond":[{"$eq":["$expenseL4","true"]},1,0]}}}}
]

The true result is:
[{
"_id" : "000.03.50.H29",
"materialLevel2" : 1.0,
"materialLevel3" : 1.0,
"materialLevel4" : 2.0
},...]

But when the length of query greater than 21066 character, the result of query is:

[{
"profileID" : "00.00.00.PTT",
"expenseL2" : "true",
"expenseL3" : "true",
"expenseL4" : "false"
},....]

Thanks!