I don't know whether this is new.
In desktop you can click edit at a section transcluded from another page. You will then edit the right section on the other page. This doesn't happen in mobile. It was reported at [[ https://en.wikipedia.org/wiki/Talk:Main_Page#Cannot_edit_ITN_from_mobile? | https://en.wikipedia.org/wiki/Talk:Main_Page#Cannot_edit_ITN_from_mobile?]]
https://en.wikipedia.org/wiki/Talk:Main_Page#Main_Page_error_reports transcludes https://en.wikipedia.org/wiki/Wikipedia:Main_Page/Errors which has the section "Errors in In the news". In desktop the section edit link at https://en.wikipedia.org/wiki/Talk:Main_Page#Errors_in_In_the_news correctly goes to https://en.wikipedia.org/w/index.php?title=Wikipedia:Main_Page/Errors&action=edit§ion=T-4 which edits the section.
But in mobile at https://en.m.wikipedia.org/wiki/Talk:Main_Page the link goes to https://en.m.wikipedia.org/w/index.php?title=Talk:Main_Page&action=edit§ion=T-4 or https://en.m.wikipedia.org/wiki/Talk:Main_Page#/editor/T-4 and does nothing.
On the transcluded page https://en.m.wikipedia.org/wiki/Wikipedia:Main_Page/Errors the link correctly goes to https://en.m.wikipedia.org/w/index.php?title=Wikipedia:Main_Page/Errors&action=edit§ion=4 or https://en.m.wikipedia.org/wiki/Wikipedia:Main_Page/Errors#/editor/4 and works.
Tested in Firefox on a Windows computer and on an iPad with iOS.
= Developer notes
I learned something new today.
* Create a page Wikipedia:Transcluded_page
* On a page https://en.wikipedia.beta.wmflabs.org/wiki/Transcluded_page make sure the content is as follows:
* Navigate to https://en.wikipedia.beta.wmflabs.org/wiki/Transcluded_page and click edit source and you will be redirected to https://en.wikipedia.beta.wmflabs.org/w/index.php?title=Wikipedia:Transcluded_page§ion=T-1&veaction=editsource
* However, navigate to https://en.wikipedia.beta.wmflabs.org/wiki/Transcluded_page and click edit on mobile and it will attempt to edit the **existing** page in the editor.
We'll need to update Skin::doEditSectionLink to use the $title passed as a parameter to the method rather than using "$this->getTitle()"