When using ../.. to type a relative link to the help page (which doesn't have a /hypha link, so that's the only way to do it without pasting the whole URL) -- for example, [[ ../../help/en/mycomarkup ]] from hypha/home -- the link works, i.e. clicking on it brings me to the intended page; but it shows up as a red link as though it doesn't work.
You can use [[/help/en/mycomarkup]] to link to the help page. Same for all other non-hypha pages, like [[/recent-changes]] and whatnot. The fact that you managed to find such a weird way to link it is a bug.
When using ../.. to type a relative link to the help page (which doesn't have a /hypha link, so that's the only way to do it without pasting the whole URL) -- for example, [[ ../../help/en/mycomarkup ]] from hypha/home -- the link works, i.e. clicking on it brings me to the intended page; but it shows up as a red link as though it doesn't work.