Redmine

I just hit the problem of a broken subtask tree once more. This is a long standing problem that I have seen and reported before. See for example:

#11011 - reported by me - ultimately closed as not reproducible.
#15581 - reported by my colleague.

I was creating a 3 level tree of bugs to be fixed using multiple tabs to add new subtasks at each level. This is how far I got:

However when I click on issue 8644 in that tree (first level child) it gets most of the rest of the tree displayed on its page:

I checked in the database and this is what I see in the left and right :

Using

select id, parent_id, root_id, lft, rgt from issues where id > 8797 order by lft, rgt;