Please make sure you run that command from inside the untarred folder, or you may be installing for a different Rust version.
But before we pursue this, would you please try the latest beta launcher? Please enable beta settings and install 25.08b4, and confirm in the about screen you’re on that version. After doing so, please try Tools>Upgrade/Downgrade again. With the latest beta + beta launcher, I’m hoping it will resolve your issue.