If you look closely at the railing, it may be associated to the stair and follow the treads and risers, but it actually seems to be set out by the same algorithm that determines the base of the stair structure.
On straight stairs or with landings this is fine.
But as soon as there are winders or curved flights, it gets very messy.
Here is a post that helps to illustrate the problem.
https://archicad-talk.graphisoft.com/viewtopic.php?f=20&t=66176#p294233
As others have mentioned you will be best not to associate the railing to the stair.
Set the heights and positions of the railing nodes yourself and you will get much better results.
I am not saying it will be easy though.
Barry.
One of the forum moderators.
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