Perspective Horizontal Menu child items all arranged horizontally

Ignition
1

I think I broke my Horizontal Menus. In the top level items are arranged horizontally, no surprise, but then child items added below the top level also display horizontally. Does anyone know how to get the children to arrange vertically?
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Thanks

2

Please see this post.

3

Perfect, the Advanced Stylesheet fix worked.

4

Please call that out there, as that thread is where we are tracking this issue.