ProtoOAMarginChangedEvent receiving issue

Hello,

An OpenAPI documentaion say that "ProtoOAMarginChangedEvent is sent when the margin allocated to a specific position is changed".

But I am trying to create and change a volume (and/or a side (BUY/SELL)) of a position (via OpenAPI and directly from app: https://app.ctrader.com)

But I don't receive any messages. Other events work well.

Could you please explain what the the scenarios of receiving this event?