Markers are not being signaled properly after add/remove.

HashMap<String, Duration> markers = new HashMap<String, Duration>();

// Add some markers to markers (1,2,3,4,5,6)
mediaPlayer.getMedia().getMarkers().putAll(markers);
// Wait until 1 and 2 are signaled
mediaPlayer.getMedia().getMarkers().clear();
// Wait until time pass marker 4
mediaPlayer.getMedia().getMarkers().putAll(markers);
// 3, 4, etc will be signaled, but not 1 and 2

Can be reproduced with FXMediaPlayer.