Map symbols disappear when zoom in and out

[pfau_tarleton]

[edit added later: this has resolved, as @einsum suggested, it was likely due to delay in indexing of observations added to the project. They are all displayed now at all levels of zoom.]

I don’t know if this is a bug, but it happens in two different browsers (Firefox and Vivaldi).

When I zoom in to different levels, different map symbols disappear and then reappear. Is this a feature, bug, or a personal problem?

https://www.inaturalist.org/observations?project_id=268293&subview=map&verifiable=any

[Edit added later: It’s related to these observations being mapped using a project ID. The same observations mapped using an observation field do not disappear: https://www.inaturalist.org/observations?subview=map&verifiable=any&field:Similar%20observation%20set=Big-eyed%20Hogna]

At this zoom level, all the points appear to be visible.

At this zoom level, many points disappear.

This one is zoomed into the El Paso, Texas vicinity (border between southern New Mexico/west Texas). At this level the points that went missing reappear.

[thomaseverest]

Are they actually disappearing? Or are the tiles just combined at coarser zoom level?

[pfau_tarleton]

Actually disappearing as far as I can see.

It’s related to these observations being mapped using a project ID. The same observations mapped using an observation field do not disappear: https://www.inaturalist.org/observations?subview=map&verifiable=any&field:Similar%20observation%20set=Big-eyed%20Hogna

[einsum]

I have seen this happen quite a few times too (not limited to projects) - map rendering at certain intermediate zoom levels misses some points.

it can only be realised as you did - by looking at higher and lower zoom levels.

sometimes its just timing thing, i am guessing if some points happened to get added recently to that filter and maybe the rendering indexing set is outdated (not sure if it gets generated dynamically fresh everytime for every zoom levels for every URL filter)