Roborock S8 Pro Ultra is a high-end robot vacuum/mop with an auto-empty/cleaning dock, typically used in busy households to reduce daily floor maintenance. A "LiDAR sensor stuck" error often points to a jammed turret (hair/debris), a failing turret motor, or impact damage that prevents free rotation.
Because navigation is core to performance, repair is usually worth attempting first: clean the turret area, check for physical binding, and replace the LiDAR motor/module if parts are available and the rest of the machine (battery, dock pumps, brushes) is healthy. Repair makes sense when the unit is under a few years old and hasn't had repeated docking or water-system issues.
Replace becomes more compelling if multiple subsystems are failing (dock wash/refill problems, repeated sensor faults, weak battery), since bundled repairs can quickly exceed the threshold and still leave you with an aging platform.