MapboxGL may get stuck

Programs using MapboxGL plugin may get stuck  when the map is being moved or zoomed.

This happens even in Qt’s examples, minimal_map and mapviewer.

To reproduce: open minimal_map, change plugin to mapboxgl, compile and run in maximized window, keep dragging or zooming in/out the map for some time. There is possibility that the program gets frozen and you have to force closing it.

I tried with Qt 5.15.16, this issue still exists.