I don't know if this is the same issue, but there is a workaround in https://github.com/gohugoio/hugo/issues/1778 https://github.com/gohugoio/hugo/issues/1778.

I don't know if this is the same issue, but there is a workaround in https://github.com/gohugoio/hugo/issues/1778 https://github.com/gohugoio/hugo/issues/1778. The TOC had been driving me crazy, and I had just learned to live with it for now, but I think the workaround can address some of the issue.