URL field + Output this field as a custom link: "#" character stripped from URI

Got a strange one today. It's possible this is a support request, I'm uncertain.

I have a node type with a title and a URL field, only displaying URI's. The entire point of the node is a link, so having a node title was redundant in this case.

I then have a view that has the URL (hidden) then the title is displayed with "Output this field as a custom link" checked off, and {{ field_url }} placed as the replacement link.

This has been working great for a few weeks, but I came across a strange edge case today.

When the URL has an anchor in it, for example:

https://uptimerobot.com/dashboard.php#mainDashboard

The URL that's rendered by Views is:

https://uptimerobot.com/dashboard.phpmainDashboard

with the # tag stripped out - a broken link.

There's a fairly easy workaround. Instead of "Output this field as a custom link" on the title field, I can select "Override the output of this field with custom text" and type in:

<a href="{{ field_url }}">{{ title }}</a>

and it works great.

I've tried different combinations of settings, but it seems that "Output this field as a custom link" is inadvertently stripping the fragment identifier prefix (#) out of URIs.