Can you not click links in Custom Elements?

I created a sample page on my site using this example:
This is more advanced code than I’m used to working with, but I wanted to a link to the countries listed.

I added a <a href="someurl">around the SPAN element it generates</a>

When viewing the generated page and element the link is visible in the status bar and it also shows in the code when I view source, but if I try to click it it never opens. I can right click and open it in a new tab but it refuses to let me just click the link.

In the console I get an error:

Uncaught (in promise) TypeError: Failed to fetch

Any ideas?

Not enough info. Maybe you should post here the link to the relevant live page.