Okay, I noticed this a long time, but I thought it was at my end probably, but I am not so sure now.
OpenStreetMap markers return a 404 error code when Inspecting a page that uses coordinates or maps.
One of the errors you'd spot on console is;
Let take the coordinate location example on the;
- Coordinate location property on Gratisdata: https://gratisdata.miraheze.org/wiki/Property:P134#P193
- A use-case on an actual entity page: https://gratisdata.miraheze.org/wiki/Q3080#P134
- This article on gp: https://gratispaideia.miraheze.org/wiki/National_Library_of_Australia
The marker doesn't load.