Calling mongo cli only returns a few lines of the output

[jmari]

I'm trying to get the output from mongo cli. While it works using LibC call, I'm not able to make it works on OSSubprocess. I need it working on OSSubprocess because LibC call blocks the image process until the child finish his job...so on libc my code is:

buildCommand
...
^ (self pathToMongoExecutable ,'mongo --eval ''' ,
		'DBQuery.shellBatchSize = ', limit asString,';', 
		'db.getCollection("', self collection  ,'")', '.aggregate(',
		queryString contents , ');'' ',
		self database,
		' 1>' , self outFilename)
....
result :=LibC runCommand: self buildCommand.

And on OSSubprocess (I've tried all of the options described in Readme file)...

totalStdout := String new writeStream.
	OSSUnixSubprocess new
					command: self pathToMongoExecutable ,'mongo';
					arguments: {	'--eval'. 
						'''DBQuery.shellBatchSize = ', limit asString,';', 
						'db.getCollection("', self collection  ,'")', 
							'.aggregate(', self buildQuery, ');'''.
						self database.};
		redirectStdout;
		redirectStderr;
		runAndWaitPollingEvery: (Delay forMilliseconds: 500)
	doing: [ :process :outStream :errStream |  
		| read |
		read := outStream upToEnd.
		"Next 2 lines is to simply update the Playground"
		totalStdout nextPutAll: read.
		errStream upToEnd.
	]
	onExitDo: [ :process :outStream :errStream  |
		(Delay forMilliseconds:5000) wait. 
		process closeAndCleanStreams.
		Transcript show: 'Total stdout: ', totalStdout contents.
	]

The output of my code using OSSp is

MongoDB shell version v4.0.3
connecting to: mongodb://127.0.0.1:27017/finhava
Implicit session: session { "id" : UUID("3a7496c6-bddf-4c04-9083-42a5782dc91b") }
MongoDB server version: 4.0.3
DBQuery.shellBatchSize = 5000;db.getCollection("TFVottunUploadedActivity").aggregate([{$match:{"product_step":1,"workflow":"00 Descarga FORM"}}]);

It finish here, using LibC I get the result after, any help will be welcome