The static map thumbnail images, shown when viewing a page with a mpaframe map, seems to be taking a long time to be generated/shown. At my sandbox (at enwiki), I made this edit at 23:03 UTC.
This added a map with two point features, via templates/modules. The equivilent wikitext for the mapframe map, by expanding templates, is
<mapframe height="200" frameless="1" align="center" width="290">[
{"type":"Feature","geometry":{"coordinates":[-83.00208694,39.962375],"type":"Point"},"properties":{"description":"39.96237500°N 83.00208694°W","title":"[[LeVeque Tower|American Insurance Union Citadel]]","marker-color":"5E74F3"}},
{"type":"Feature","geometry":{"coordinates":[-82.997111,39.942111],"type":"Point"},"properties":{"description":"39.942111°N 82.997111°W","title":"[[Krumm House|Krumm House]]","marker-color":"5E74F3"}}
]</mapframe>Half an hour later, along with multiple purges, null edits, and a dummy edit, the page looks like this when viewed (left) and previewed in the wikitext editor (right):
The preview of course uses a dynamic map rather than static image, so shows the two point features as expected. When viewing the article, the expected result is the same or very similar view but as a static image, but instead the zoomed-out world map is displayed.
For some reason, maybe bad caching or a race condition, an empty GeoJSON layer is initially being used instead of the actual GeoJSON when generating the static thumbnail; if no coordinates are explicitly set, this results in the default map being rendered.
The same thing happens at https://en.wikipedia.org/wiki/User:Evad37/Sandbox_10, which is using the mapframe tags directly rather than via templates/modules.
A very similar mapframe map, but with like 168 other point features, is currently displaying correctly for me at National Register of Historic Places listings in Columbus, Ohio, but a few hours ago another user reported that the map was broken (at https://en.wikipedia.org/wiki/Template_talk:NRHP_row#Wikidata_coordinates)