DETROIT (AP) — U.S. safety regulators are investigating complaints that a Ford pickup truck tailgate recall didn’t fix the problem.The National Highway Traffic Safety Administration says it has 11 complaints that a recall of power tailgates on 300,000 Super Duty pickups didn’t work.Ford recalled the F-250, F-350 and F-450 trucks in 2019 because the power tailgates could open while being driven. That could let unrestrained cargo fall out. The trucks are from the 2017 through 2020 model years.The agency says it also has received reports from Ford about unintended tailgate openings after recall repairs were made.A message was left Wednesday seeking comment from Ford.