EXTERIOR LIGHTINGTonight, shortly after dusk, on a lightly traveled road near my home, the high-beams failed to function as described in the manual, or according to any alternative way to activate them. Traffic is 30 MPH with a single lanes divided by a double yellow center line with cat-eyes. This area frequently has deer and other wildlife. Accordingly, whenever possible, high beams should be activated. Conditions were dry, and clear, without oncoming traffic -- while driving at or near the posted limit. Pushing and persistently holding the high-beam light maintained high-beam only while pressing the high-beam marked part of the steering wheel. Typical operation, in the past, operated the high beam if the button (capacitative sensitive surface on the steering wheel) was held in for about a full second and then released. This is no longer how it operated tonight. Driver pushed the high-beam for a full second. Upon release the high beams reverted to normal low beams. Driver repeated this 2 more times. After doing this twice, the driver is already distracted from wildlife and starting to focus on the car -- looking for error messages of some kind. After three times, its clear that it is Tesla software that is broken. Although the car is in good repair, no messages were presented. Again, conditions were clear and dry. Failure to operate visibility mechanisms is highly contrary to safe driving. Some features which should always work: 1. Wind shield wipers; 2. Defogger 3. Defroster 4. head lights 5. high beams Hopefully, Tesla has not abandoned functional high-beams like they have with Full Self Driving. On the other hand, if FSD is no longer among the executive compensation goals, perhaps providing a visible landscape to the all-camera FSD algorithm is also superfluous.