Previous controller still alive while on another controller

[SmartHbdev]

When I am on controller A, open the menu, click to open controller B, it works.
But if I make some changes on controller B with core data, I see the logs of controller A moving.

Is it normal that the previous controller is alive?
Controller B is called from the menu, there should be no push chain to keep controller A alive

Can we kill it somehow?
Because the operation on controller A may take some time.