Two images on one line: only one redirects to imgur

When I’ve got two images on one line, only one of them links to imgur. The other one links to my local image.

I select two images using “Add Media” button, and it adds markup like this:

<a href="https://example.myblogs.com/files/2014/11/file1.png"><img class="alignnone" src="https://example.myblogs.com/files/2014/11/file1-168x300.png" /></a> <a href="https://example.myblogs.com/files/2014/11/file2.png"><img class="alignnone" src="https://example.myblogs.com/files/2014/11/file2-237x300.png" /></a>

On the page, it shows code like this:

<a href="https://example.com/files/2014/11/file1.png"><img class="alignnone" src="https://example.com/files/2014/11/file1-168x300.png" /></a> <a href="https://i.imgur.com/jdoe93j.png"><img class="alignnone" src="https://i.imgur.com/dj2jsk3.png" /></a>

I don’t know if this makes a difference, but I’ve got a multi-site with domain mapping (hence why example.myblogs.com becomes example.com).

https://www.ads-software.com/plugins/wp-imgur/