Using Module:Mapframe with Template:Maplink on English Wikipedia
Sometimes the map thumbnail spontaneously stops showing. Yesterday I edited all sections of "Interstate 95" (read "Interstate 95 in Florida", in Georgia etc. - about 13 pages) to remove fixed lat/lot and zoom from template to allow for auto position and zoom ([[ https://en.wikipedia.org/w/index.php?title=Interstate_95_in_Florida&diff=909352572&oldid=907992070 | sample edit ]]). I was logged in and the thumbnails showed for me. After few hours now the thumbnails do not show for the Maplink template on all the 13 pages. Switch to Template:MapframeForObjects at "Interstate 95 in Florida" again helps to show the thumbnail, question is for how long.
Besides the missing thumbnail the full screen map work properly also showing the feature.
Do we need static thumbnails? The preview page uses dynamic thumbnails (also adds + and - icons to it for zoom). I guess leaving dynamic thumbnail is technically simpler and less prone to infrastructure errors/outages but surely will load the tile server (which surely has cache too).
This may have something in common with my other issue of thumbnail having problems to show when logged in (is opposite problem). Maybe as I was logged in while editing a "false" thumbnail was shown and maybe at the same time no thumbnail would show for anonymous user. I filed a bug for this issue but can not find the ticket now. Will add it later.