Using Steam installed via the overlay will result in Origin connection errors with both Titanfall 2 and Jedi: Fallen order.
Titanfall 2 gives the error "we are unable to connect to ea servers to activate displayname field missing try again later"
Jedi: Fallen Order gives the error "we've noticed your computer is currently offline, to activate your game on this computer using your ea account you'll need to connect to the internet"
However, when using the Flatpak steam client on the same computer, both games run fine.
I have the steamruntime USE flag set, and I have also tried installing steam-runtime-openssl. It seems that some package is missing on Gentoo, but I wouldn't know where to look.