Atlas Overlay Inconsistencies

I’ve started looking at some Atlases more closely and I’m finding they’re weirdly inconsistent with respect to what is actually being displayed on a taxon page. If a country is exploded, sometimes you get the country, sometimes you get the subparts, sometimes you get both, as you zoom in regions will appear and disappear.

For example,

Completely zoomed out, the only overlay you can see is orange for Sri Lanka and Bangladesh. Go in about two zoom steps and you get a bunch of regions of India, but Sri Lanka disappears. Zoom in a bit further and all but a single Indian region disappear from the map. Makes no obvious sense that I can determine.

At wide zooms, why doesn’t the containing country display, only shifting to exploded regions (if present) at smaller zooms? Other atlases on the site seem to work this way (e.g.,

Related, some of the overlays seem to disappear if they cannot be shown in their entirety, while others stay displayed regardless. Again, cannot see the reason why this is occurring.