Rendering issue with map position/zoom + tileset w/Features per zoom level

[ksummerill]

mapbox-gl-js version: 0.44.2

Steps to Trigger Behavior

1. Open this map: https://bl.ocks.org/j5kay/a50925604a76c892826e5d3a7db77ddd
2. Click and drag to move around the map, observe rendering behavior.

Expected Behavior

Map rendering is smooth and consistent as you move around the map

Actual Behavior

Rendering is jumpy, appearing and disappearing - https://ookla.d.pr/GoSLAX

[jfirebaugh]

Is mapbox://ookla-ops.coverage-carrier-3221 a partial tilset, not covering the whole world? If so, I suspect this is a variant of #5829 / #4691, where when GL JS encounters a 404 response for a tile outside but adjacent to the boundary of the tileset, which triggers loading the parent tile, which also covers tiles at the natural zoom level that do exist.

[j5kay]

@jfirebaugh - Yes, it has data not only within the LngLatBounds specified in the tileset's TileJSON, but also has features on a per-zoom basis between its z=0 to z=10 zoom extents (also specified in the TileJSON).

Not sure if the per-zoom tile data also plays a role per se, but when using circle-based layers for rendering data, it seems that multiple zoom levels are merged versus the exclusive rendering for heatmap or extrusion-based layers. Maybe a separate issue entirely, but I could make an example that illustrates the behavior with circle layers, if it's useful.

[jfirebaugh]

Thanks for the report! I'm consolidating all the issues related to this bug in #6768.