When using a QSortFilterProxy that filters according to items being present on QML Map item visibleRegion.boundingRectangle() and zoom below a certain level, moving the map creates artifacts on Map.
When moving the map, you can see items fade out and in.
It's best clearly seen when zooming out to when the filter proxy has 0 items, but you still see some on the Map. (See attached images)
This issue did not occur on Qt 5.10.1, but started in Qt 5.11 and is still present in the current 5.12.0 beta. The Map is also much more responsive in 5.10.1 than the other versions, but I don't know if it's related to this issue.
I've attached the example program I used to test this.