Reproduction:
git clone --single-branch -b broken-anchor-links https://github.com/deining/hugo-test hugo-broken-anchor-links
cd hugo-broken-anchor-links
hugo server
In your browser, invoke:
http://localhost:1313/en/s1/p1/
Click on the link at the top of the page. You are redirected to the site root, where the anchor link cannot be found.
The anchor link works fine with hugo v.0.122.0.
Thanks for looking into this!