Enabling, disabling a replacing tracks after connection negotiation

[matejszabo]

Hello,
We are developing a conferencing solution with KMS as our media server (running 7.1 now on Docker, The client app is built with kotlin multiplatform, the signaling backend is Java, connecting to KMS via the client lib). The requirement is, that a user is by default only listening on join, and they can later arbitrarily unmute themselves and/or stream their video. When the user joins with both outgoing video and audio, everything works fine (so the pipeline is constructed correctly and there are no network issues), but I was not able to achieve the desired behavior, neither with both getting userMedia on peerConnection construction and immediately disabling them, nor with replaceTrack(...) with re-getting userMedia on outgoing track enable event. Every time it fails with error:
WebRtcEndpoint error:Error code 1: Internal data stream error., source: nicesrc66, element: kmswebrtcendpoint66, debug info: ../libs/gst/base/gstbasesrc.c(3177): gst_base_src_loop (): /GstPipeline:pipeline64/KmsWebrtcEndpoint:kmswebrtcendpoint66/KmsWebrtcSession:kmswebrtcsession66/KmsWebrtcTransportSrcNice:kmswebrtctransportsrcnice66/GstNiceSrc:nicesrc66:
streaming stopped, reason not-linked (-1).

Is enabling/disabling (video) of streams supported by Kurento, and if it is, what is the suggested way to do it?