Stumbling on the stairs

[Xizi]

What makes avi stumble on the stairs and how to fix it? There is one place at my home, and no matter what I do - make stairs longer, shorter, higher, lower - my avi keeps stumbling. Sometime more, sometime less - but always stumbling in one place before go through it. 

[Torax]

The top of the stairs need to be slightly above the piece you connect to it, and top part needs no to be above the other element. Not sure I am clear.

[Xizi]

1 minute ago, Torax said:

The top of the stairs need to be slightly above the piece you connect to it

In my case it works, but only when top of the stairs significantly above the floor it connected to. Well, if we talking about fully remove of stumbling. To reduce it to more or less comfortable amount - it's enough to make it slightly above.

4 minutes ago, Torax said:

and top part needs no to be above the other element

Not sure what do you mean here, sorry. 

[Torax]

Well, the last step of the stairs, the top part, should be connected right at the level the angle change. Sorry for my english. The flat top part out of the floor it is connected to.

Edited September 4, 2019 by Torax

[MeiLing]

The last step of the stair must be aligned with the floor. And only the beveled part must be inside the floor. And the same for the lower part

Edited September 4, 2019 by MeiLing
add missing word "be"

[Xizi]

Thanks!