mime-types, default apps - default video app across all OS

[SockThief78]

I have Showtime set as a default video app. However when I double click a video file in content tab of qBittorrent it opens in VLC. Double clicking video file anywhere else opens Showtime.
If I uninstall VLC double clicking a video file in content tab of qBittorrent opens Showtime. After reinstalling VLC, qBittorrent defaults to VLC again.
Checked all config files I know of and factory reseted qBittorrent (I deleted all config files).

Why does it happen? How to change this?

[SockThief78]

https://app.dosu.dev/e3630b91-3a35-46b9-a8d3-b0c1b3ef6331/ask?thread=74fe6c2c-bfd6-413b-a910-018231c76b30

This is my discussion with dosu

"The D-Bus trace proves the issue is 100% in portal handler resolution — not in qBittorrent itself. Something in the MIME resolution chain is putting VLC ahead of Showtime despite your explicit defaults."

Unfortunately I didn't manage to pinpoint the problem yet. Send help :)