When I zoom in/out a few times across the map, some of the tiles seem to disappear at certain extents. <img width="1200" alt="tiles_partialLoad" src="https://user-images.githubusercontent.com/3245803/114780526-85eae480-9d45-11eb-9205-44965e9846b1.png">
When I zoom in/out a few times across the map, some of the tiles seem to disappear at certain extents.