The Being 787 Max did that when the sensor got faulty and there was no redundancy for the sensor's because that was in an optional addon package

All the other answers here are wrong. It was the Boeing 737-Max.

They fit bigger, more fuel efficient engines on it that changed the flight characteristics, compared to previous 737s. And so rather than have pilots recertify on this as a new model (lots of flight hours, can't switch back), they designed software to basically make the aircraft seem to behave like the old model.

And so a bug in the cheaper version of the software, combined with a faulty sensor, would cause the software to take over and try to override the pilots and dive downward instead of pulling up. Two crashes happened within 5 months, to aircraft that were pretty much brand new.

It was grounded for a while as Boeing fixed the software and hardware issues, and, more importantly, updated all the training and reference materials for pilots so that they were aware of this basically secret setting that could kill everyone.

Pretty sure that's the Boeing 777 and they discovered that after a crash off Brazil.

For mine, it’s the radar seeing the retro-reflective stripes on utility poles being brighter than it expects.

They've had it forever. Tie a rope to the wheel. Presto. Autopilot.

They've technically had autopilots for over a century, the first one was the oil tanker J.A Moffett in 1920. Though the main purpose of it is to keep the vessel going dead straight as otherwise wind and currents turn it, so using modern car terms I think it would be more accurate to say they have lane assist? Commercial ones can often do waypoint navigation, following a set route on a map, but I don't think that's very common on personal vessels.