The most likely factor behind this incident is pilot fatigue, which has caused similar incidents in the past. AngoAviação reported on ITA Airways pilots who fell asleep over France and caused a scare of terrorism, which was probably also due to fatigue.
Airlines are required to implement Rest Fatigue Management Systems (FRMS) to ensure pilots get enough rest and are not overworked. However, given the ongoing staff shortages in the aviation industry, many airlines are desperate for pilots and will be maximizing the hours of their existing pilots.
Wizz Air CEO Josef Varadi recently caught the attention of pilots complaining of fatigue, urging them to “go the extra mile”, prompting backlash from many in the industry.