After a non-exhaustive search around various water-bodies of the world, the only examples of the tile problem I came across were in the Great Lakes. At various zoom levels on Huron and Superior quite a few blocks show up, and each block appears to be consistently there at its 'problem' zoom levels. On Michegan I only found a few errant tiles, eg at Pentwater (But that doesn't mean there aren't more at zooms/locations I didn't check) and I saw no problems in Lakes Ontario or Erie.

There are still some odd goings-on with white tiles in the middle of some of the Great Lakes, and also (and I have not seen this before) some strange green parts over what should be lake. eg en:Bruce Peninsula has an OSM Location map on which I am seeing both green and white oddities. If you click on the interactive link you can also see different white tiles and green 'shore extensions' at different zoom levels in maplink, Maybe this is just a transient bug, and thanks for those who have worked on this.

Lake Huron now seems to be present, but Lake Michigan goes white at various zoom levels. England and Wales National Parks have lost their green colour except for random individual tiles at very high zooms. People will rapidly lose confidence in the maps if major features such as lakes and islands are absent.

Lake Huron in Canada has the same problem. Has anything been identified on this? It makes all the maps of southern Canada/Great Lakes very disorienting. Probably not relevant but Maggiore and Huron both have intersecting political boundaries running along them. Could that be a causal issue?

I am currently seeing Lake Huron entirely white on most zooms, and with some white tiles on zooms above 9. (on Wikimedia maps: https://maps.wikimedia.org/#7/44.674/-82.213 and across various implementations of maplink, and graph templates). Is this a cache issue from last time or has the problem re-emerged? @Gehel was able to do an OSM replication last time. Did that resolve it, and how has it returned? It looks fine on the OSM site.

I am working in a bit of a fog of ignorance here, so will describe what I have done and if someone thinks it doesn't make sense, please sort it, or point me in a better direction:
The en.wikipedia.org/wiki/Template:Graph:Chart/styles.css had some additional css as well as the lines above, so I copied all of that into new styles.css files for both en: and mediawiki versions of {{Graph:Street map with marks}}. I then copied - again from en.wikipedia.org/wiki/Template:Graph:Chart - the instruction {{safesubst:#tag:templatestyles||src="Graph:Street map with marks/styles.css"}}, to invoke it. (no idea about safesubst but I assume it makes sense).
I am not familiar with how the mediawiki version gets applied across other languages, so have not done anything about that. Nor am I familiar with how to find which other Graph templates might need the fix (as opposed to ones that call other graph templates).

Awesome. I have incorporated it below the map on OSM Location map, so it will be there on any page needed. Its a fudge, but a pretty good one! I am guessing Graph:Chart found a way to turn off the lazy loader.

Is there any progress on this? It blanks out all lazy-loaded maps dependent on 'Graph:street map with marks', as well as other graph images. I think the lazy image loader may also be knocking out the GeoJSON markers on some <maplink> maps that include a 'marker-image', although the en.template version seems to be not affected. (Examples of various affected maps are at https://en.m.wikipedia.org/wiki/User:RobinLeicester/sandbox).

On en: and various other wikipedias there is a Maplink template. Using it on an article with a defined coord means you can simply add {{Maplink|frame=yes}} which will give you a first stab at a map using the pages coordinates and default sizes.

Any chance of this making any progress? It would be a major loss if the 'Graph' maps got left out of the internationalized names.