Hello @BlueGoliath, the current Steam client beta is expected to use xdg-desktop-portal for this. It's highly likely your system has been configured to use vscodium for this type of dialog similar to https://github.com/VSCodium/vscodium/issues/409.
This configuration is user choice and not a Steam bug.
But why?
See https://github.com/ValveSoftware/steam-for-linux/issues/9516 for system details.