On 6 November 2019, upon their return to Da Nang International Airport, Mr. Huynh Ngoc Truong, Ms. Nguyen Thi Hoai Phuong, Ms. Nguyen Pham Ai Thuy, Ms. Ngo Thi Lien and Mr. Thich Thien Phuc were reportedly stopped by security officers and separately subjected to intense interrogation about their participation in the conference, including what the conference was about, who the organizers and participants were, how they funded their travel, and what they had shared or done at the conference

On 14 November 2019, in the context of an eviction of residents in the village of Con Dau Parish based on an order issued in 2011, many police officers surrounded the houses of Mr. Huynh Ngoc Truong and Ms. Nguyen Thi Hoai Phuong. Fearing that it was an act of reprisal for having participated in the 2019 conference in Bangkok, they went to Lao Bao border in Quang Tri Province and attempted to cross to the Lao People’s Democratic Republic for safety. However, Mr. Huynh Ngoc Truong was detained and interrogated by the police before crossing the border. When he was taken by a police officer to a nearby hotel to spend the night, he was brutally attacked by a group of men until he fainted. They only stopped when a police officer intervened. On 30 November 2019, Mr. Huynh Ngoc Truong was again detained on a bus to the Cambodian border at Moc Bai and interrogated for twelve hours about his past activities defending the religious freedom of his parishioners, and about the 2019 conference in Bangkok (VNM 2/2020).