[bug?] Different behavior when I put a composite shot in the editor timeline (missing reflection...)

Hi,

I have a very odd behavior when a put a perfectly working composite shot in my timeline.

*** Within the composite shot (Intro5) ***

I have both reflections on the right and on the left of the screen, in particular you can see reflection under "ça" (which is a composite shot of a text with surface studio effect, extruded in 3D) and the balloon. This is want I expect

*** When I simply drag the composite shot in the timeline ***

Reflection on the right is still there BUT not under "ça" and the balloon. When I render the file, the reflection is also missing (which is not the case when I directly render the composite shot". I'm totally puzzled... What's going on here? Did I do something wrong?

Here is the sample project with the bug : https://1drv.ms/u/s!AkN-MiCixbTCmI9ZZKX6QW7ghZQjtQ?e=sBxdnv (check composite shot "Intro5")