Slot content is not rendered in foreginObject, when forigenObject is root tag of separate component

[alaroma]

Version

2.6.11

Reproduction link

https://codesandbox.io/s/epic-neumann-m8hqz

Steps to reproduce

Open link

What is expected?

Should display button under the text

What is actually happening?

Button is not displayed

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I try to add separate vue component in svg. This component has foreginObject tag as root and contains button, wich was inserted thorought slot in another component. It do not work, I mean button is hidden in browser. However the button exist in DOM, more over has sizes

At the same time if forigenObject tag is declared in component with svg it is work. I can see button.
example: https://codesandbox.io/s/inspiring-mclaren-t1z09

I supose, there is porblem with slot content rendering in foreginObject, when forigenObject is root tag of separate component

[posva]

Duplicate of #11315