The lane keeping assist function has disappeared from my Model 3. It used to work, and appears to still be switched on in the software settings. Am I missing something? It initially worked with the "virtual rumble strips" (shaking the wheel when drifting over lines) and then changed to actual steering correction if I drifted towards the line. Now neither happens at all. This issue is when NOT using Autopilot. When Autopilot is engaged, the vehicle follows the lane lines with few issues.