Anchor links don't work with the Excerpt macro on Knowledge Bases

Steps to Reproduce

1. Create JIRA SD project and link to a Confluence Space with KBs.
2. On KB X, add a TOC Macro and add headers for the macro to reference. i.e. Heading 1. Make sure that the TOC macro has (absolute urls turned on).
3. Wrap the TOC Macro in an Excerpt Macro
4. On KB Y, insert an Excerpt Include referencing KB X
5. Go to the customer portal and search for KB X and Y.
6. Click on the anchor links from KB X.
7. Click on the anchor link from KB Y.

Expected result
Clicking on the links from KB X should redirect to the respective KBs as the links on the titles do, or like the link from KB Y.

Actual result
When clicking on KB Y link, it reopens the KB as a document. When clicking on the anchor links from KB X, it redirects to the customer portal.

Notes:

It seems to be related to the previously reported Confluence bug: https://jira.atlassian.com/browse/CONFCLOUD-53948, but it seems to be affecting linked KBs only.

Workaround

Use normal anchor links without the Macro as on KB Y.