Issue recording a new canvas stream with Kurento Recorder

[kyris9]

Hello all.

I am using kurento-utils, v7.0.0, to stream and record a videocall between two users.
I am using Kurento Media Server 7 and the file format of the recorded videos is in WEBM.
I am altering one of the user's video by using a canvas to create a background image filter.

I have noticed that if I pass the canvas stream as the videoStream parameter in the WebRtcPeer.WebRtcPeerSendrecv() method, I am able to see the altered video on the receiving end.

However, when I check the recording it has a filesize of 0.

I've tried manually changing tracks and sending the video's stream instead however I would either not see the expected result on the receiving end or the recorded filesize would be 0 bytes.

Is there anything that would make Kurento recorder to record the canvas stream that is sent?

Thanks in advance.