Bug: mux-player childList observer behavior

[IlyaRazuvaev]

Is there an existing issue for this?

• I have searched the existing issues

Which Mux Elements/Packages does this apply to? Select all that apply

mux-player

Which browsers are you using?

Chrome

Which operating systems are you using?

macOS

Description

Hello!
I'm working on integrating a custom element into mux-player, and I'm having trouble with web components. I need to insert an element into mux-player with styles that are loaded directly into the page.
I'm using a similar approach to how Mux handles the poster slot, passing the element through the slot tree like this:

<slot name="my-slot" slot="my-slot"></slot>

However, when I do this, the internal structure of my custom element is unexpectedly copied into the mux-video element, which breaks the UI of player element.

Reduced test case

https://codesandbox.io/p/sandbox/t86gpf?file=%2Findex.html%3A7%2C35

Steps to reproduce

1. Open sandbox
2. Observe elements of mux-video
   

Current Behavior

Elements are copied

Expected Behavior

Top level elements are copied only. (My assumption based on the review of the code related to @mux-player/src/video-api)

Errors

No response

What version of the package are you using?

Latest