A curious thing about PiP and Wayland

Currently PiP isn’t supported on Wayland, but recently I finally discovered how to create a Window rule to force the PiP video window to automatically be forced to stay above other windows. The effect is undistinguished from the expected correct behavior, except for when I try to upload something somewhere.

When I’m on Mastodon for example and click the button to upload an image, when the file picker opens it makes the PiP video window go away.
What is curious about it is that when the file picker is open for the opposite purpose, download instead of upload, like when I want to save an image or file in these cases the file picker does not make the PiP video window go away.
Why? It’s the exact same “xdg-desktop-portal-kde org.freedesktop.impl.portal.desktop.kde” program being invoked in both cases.

Anyone has any idea for how to prevent the file picker portal from making the PiP video window go away when uploading files?
I tried everything with the Window Rules, is it not possible?

EDIT: forgot something importante. This only happens when using PiP on Vivaldi (chorume based web browser), it doesn’t happen on Firefox.
So if you use Firefox as default and wants PiP on Wayland, create this rule: