"Automaticlly copy selection" is invalid

I have checked Session->Perferences->Settings->Text->Features: "Automaticlly copy selection",
But when I box the characters with the mouse, they are not copied to the system clipboard.

To add: doesn't work in archlinux, works in win11

Reproduce the “Automatically copy selection” setting from Session > Preferences > Settings > Text > Features on Arch Linux, then compare its behavior with Windows 11, where the report says it works. Trace the implementation of this setting and the system clipboard path; done means selecting text copies it on Arch Linux without regressing Windows behavior.

Written by the indexing model from the issue text.