Mac os get position of window is stepped & delayed

Hi all,
I’m currently working with libVlc to create a video-player. I give vlc the handle of a window without a titlebar to do its drawing. This videooutput-window is in front of my main-window and I want to sync both, so the videooutput-window appears like a component within the main-window.

On windows this is no problem, I use the ComponentMovementWatcher class and give my video-window the new position whenever the main-window is moved/resized. But on mac, the position of the main-window seems to be updated much less frequenlty, causing the positioning of the video-window to be really laggy when moving the main-window around.

I also tried updating the position of the video-window with a timer at 30Hz, and logged the positions I get when moving the main-window. It gives the same value about three times before it updates to a new value wich is at least 10 pixels away from the old one, no matter how slow I move the window.
The resizing of the window works fine its only the movement.
System is a mac pro with HighSierra 10.13.

Has anybody dealed with this and has a solution?