Passenger reached Udaipur instead of Patna by mistake of Indigo: second incident in a month

Indigo Airlines took the passenger who left Delhi to Patna to Udaipur. When the airlines realized their mistake after the passenger's complaint, he was sent back to Patna the next day. The passenger has complained about this to the Director General of Civil Aviation (DGCA). DGCA has ordered an inquiry into the matter.
Indigo has done this for the second time in a month. Earlier, on January 13, the airlines had taken the passenger going from Indore to Nagpur. Here, after the passenger's complaint, the DGCA sought a response from the airline company. Before boarding, the boarding pass is checked at two points as per the rules, so how did he board the wrong flight?
DGCA official said – The name of the passenger is Afsar Hussain. Hussain had booked a ticket on Indigo flight 6E-214 to Patna. On 30 January 2023, Hussain reached Delhi airport on time for his flight but was mistakenly put on flight number 6E-319, which was going to Udaipur. When the traveller reached Udaipur, he realized his mistake.
After this, officer Hussain complained about this to the officials at Udaipur airport. The airline then brought the passenger back to Delhi by flight on the same day. After a day's stay in Delhi, he was sent to Patna by flight on 31 January.
A DGCA official told – We have received a complaint from the passenger. Before boarding, the boarding pass is checked at two points as per the rules, so how did he board the wrong flight? The probe will ascertain why the passenger's boarding pass was not scanned properly. We have sought a report from the company on this matter. Appropriate action will be taken after the investigation of the matter.
Indigo issued a statement on the matter on Friday saying – We are aware of the incident that happened with a passenger in 6E-319 Delhi-Udaipur flight. We are in talks with the authorities in this matter. We apologize for the inconvenience caused to the passenger.