https://zh.wikipedia.org/wiki/淡路島 goes to https://maps.wikimedia.org/img/osm-intl,9,34.383333333333,134.83333333333,270x200.png?lang=zh&domain=zh.wikipedia.org&title=%E6%B7%A1%E8%B7%AF%E5%B3%B6&groups=_f827e130f18a80feb368547f3f916418efd3a811

https://zh.wikipedia.org/zh-cn/%E6%B7%A1%E8%B7%AF%E5%B3%B6 goes to https://maps.wikimedia.org/img/osm-intl,9,34.383333333333,134.83333333333,270x200.png?lang=zh&domain=zh.wikipedia.org&title=%E6%B7%A1%E8%B7%AF%E5%B3%B6&groups=_ad5e47f00f37dccc49dfeb7362457be80aad4de1 which says "GroupId not available"

Pretty sure this is the exact same issue as T222604: Kartographer maps with "type": "Feature" and a image in the description is not shown in mobile view

Try these parameters for mapframe.

<mapframe zoom="15" frameless="1" align="center" height="200" latitude="33.7241" longitude="135.9944" width="270">
[
    {
        "type": "Feature",
        "geometry": {
            "coordinates": [
                135.9944,
                33.7241
            ],
            "type": "Point"
        },
        "properties": {
            "title": "TITLE_TEXT",
            "marker-color": "#5E74F3"
        }
    }
]
</mapframe>

Case 1. TITLE_TEXT = 日本 (The text is the same in all variant)
OK: https://zh.wikipedia.org/zh-cn/User:A2093064-test/mapframe1
OK: https://zh.wikipedia.org/zh-tw/User:A2093064-test/mapframe1

Case 2. TITLE_TEXT = 載 (載 in zh-tw variant equals 载 in zh-cn variant)
Broken: https://zh.wikipedia.org/zh-cn/User:A2093064-test/mapframe2
OK: https://zh.wikipedia.org/zh-tw/User:A2093064-test/mapframe2

Case 3. TITLE_TEXT = 载 (載 in zh-tw variant equals 载 in zh-cn variant)
OK: https://zh.wikipedia.org/zh-cn/User:A2093064-test/mapframe3
Broken: https://zh.wikipedia.org/zh-tw/User:A2093064-test/mapframe3

Case 4. Put 2 <mapframe> in one page. And one TITLE_TEXT = 載載, anthoer TITLE_TEXT = 载载 (載 in zh-tw variant equals 载 in zh-cn variant)
OK: https://zh.wikipedia.org/zh-cn/User:A2093064-test/mapframe4
OK: https://zh.wikipedia.org/zh-tw/User:A2093064-test/mapframe4

Why it isn't broken in my sandbox (case 2)?

https://zh.wikipedia.org/zh-cn/User:Fireattack/%E6%B2%99%E7%9B%92

In T246314#6025302, @fireattack wrote:

https://zh.wikipedia.org/zh-cn/User:Fireattack/%E6%B2%99%E7%9B%92

It's broken on my device. See also: https://archive.vn/DmlT6.

Variant isn't fully supported for api calls (where the img generation depends upon). Support for variants will have to be added for Kartographer, Kartotherian and MediaWiki-API.

In T246314#6025304, @Xiplus wrote:

In T246314#6025302, @fireattack wrote:

https://zh.wikipedia.org/zh-cn/User:Fireattack/%E6%B2%99%E7%9B%92

It's broken on my device. See also: https://archive.vn/DmlT6.

Yeah, it is broken now. Probably just cache before. Thanks for confirming.

Note for later. Keep in mind T168601: Wikicode in map data in all projects is parsed against en.wikipedia.org if data is from SPARQL

This problem is already affected to view location about something (such as a station, a city, etc), please fix it ASAP!

In T246314#6236911, @VulpesVulpes825 wrote:

@toorich, are you planning to fix this issue by yourself? If not, I am resetting the priority following the Phabricator convention and etiquette.

I'm sorry but I can't fix it, and you can reset it.

I think we can generate GroupId by {{PAGENAME}} instead of title which converted by MediaWiki.