Whenever you go to a map pin, say for example CITY A, and then link that pin to an article, say CITY A HISTORY, then usually you can click the pin, the dropdown menu will appear with linked articles, and you can click the article which will then open.

Recently, all linked articles and locations etc that are linked to a map pin are not actually linked - they simply do nothing. When hovering over the hyperlink, the link preview readout is: "0" which makes me think the function that actually generates a hyperlink is not working, as there is no destination address linked to the article. please see image of readout below:

Create map - create article - create pin within map - edit pin to link to article - click on pin in map - click on article link which has now appeared.