The Confluence has a helpful page for creating anchor links in content. Here's a lovely screen cap of what I'm trying to get:
https://confluence.atlassian.com/doc/anchors-139442.html
Apparently, when I click "Link", or Ctrl-K, I should see a sidebar with options, like "Advanced".
All I'm seeing is a helpful floating dialog with suggested links. No sidebar and no "Advanced" tool to link to existing anchor tags. I have widened my viewport to ensure that it's not a responsive issue.
Entering "#myanchortag" is not recognized in this floating dialog and unable to save. I understand that Confluence has presented an upgrade to its UI, but I'm reticent to dig through the changelogs. I'm unable to find where there is a setting to enable this in Confluence.