The Loftia demo’s October 21 patch fixed being unable to rebind controller buttons while using a controller. If remapping is still failing, check that you have the updated demo, then distinguish a binding problem from the separate menu-navigation and input-focus issues.
Use the supported menu input
In the demo’s settings menus, use the D-pad to navigate and adjust options. Thumbsticks are unsupported for this menu navigation. An option that does not respond to the stick is therefore not necessarily a failed button remap.
After changing a binding, test the affected action in its normal context. Note both the original button and the replacement when reporting a remap that is not retained or does not work.
Restore gamepad focus after mouse input
Mixing keyboard and mouse with a gamepad can leave the Loftia cursor visible. The known-issues instructions say to click into the Loftia window to re-enable gamepad input. This addresses the input state; it is not a new binding or a controller reset.
Recognize unrelated gamepad limitations
The login screen’s Select Region button may fail to highlight correctly even though it functions. The demo also cannot currently be quit from the login screen using a gamepad; the in-world menu provides a quit route.
These limitations should not be treated as proof that all remapped buttons failed. If the specific binding still fails after the patch, report the controller model, action, old and new buttons, and whether you switched between mouse and gamepad input. No particular Steam Input layout or external remapping utility is established as a universal fix.