Check your flatpak permissions for starters.

Flatpak apps operate more like containers and not a full blown sandbox, unless that has changed recently.

This is an interesting blog post on the subject: https://hanako.codeberg.page/

Also, try flatpak run org.mozilla.firefox to see if you can launch a browser manually.

Disclaimer: It’s been a bit since I have used flatpak, so take that into account. However, I do work in security by trade, so my quick notes may point you in a decent direction at a minimum.

Build a live boot USB for windows: https://monovm.com/blog/how-to-create-a-windows-live-usb/

There is a chance that the exe is just a wrapper for a compressed archive that contains the app to flash the bios and also the image. If the bios actually supports flashing manually, that would be super convenient.

De-escalation is easy: Russia can get the fuck out of Ukraine. All of it.