Modal window stays on top

I’m using Bambu Studio via a Flatpak on Linux.

The application works well, but, when I open a modal window in the program, like right after clicking File, if I don’t close this window it will stay on top of all other windows in all other programs. This pollutes my desktop environment until I switch back to Bambu Studio and close the window. I did notice a possible related issue at [Bug Report] Menus don't stay on monitor, but it’s not the same.

How can I resolve this issue/make certain this Bambu Studio modal window stays with the program and not outside of it?

Thanks.