Hello. This is just a situation report to add to the general knowledge base. I don't need any assistance with this, I just want to report the phenomenon in case it is useful for someone else.
Situation: I had a topic called "HTTP Live Streaming."
Everything worked fine when I published to HTML, and no errors were reported. If you clicked the "HTTP Live Streaming" item in the TOC, it would jump to that topic. BUT! If you copied the link (as reported at the bottom of the page, e.g., https://mysite.com/help/index.html?http-livestreaming.htm ) it would not jump to the topic; it would go to the default topic (i.e., the landing page).
I could find no problem with the link, so on a hunch I changed the topic ID from "http-livestreaming" to "hls" (i.e., I removed "http" as the first four characters). That fixed it.
It seems that having a topic ID start with "http" confuses the browser, as it thinks it's going to be a full URL and not just a topic ID. I tested this on two browsers (Chrome and Firefox) and the problem occurred in both and was fixed in both when I changed the topic ID.
File this under "FYI."