In 2023, he was surrounded by a controversy as he was found to possess forged Indian documents including birth certificate, electoral voter identity, Aadhaar and driving license.

[7] His younger sister, eight years his junior, died at age four when, at the same time his mother, Laldinpari[6] was diagnosed with cancer stage three when he was in middle school.

[10] He made the grand final on the weekend of 28 December 2019, alongside Esther Dawt Chin Sung and Aye Mya Phyu.

[20] Sum was involved in the protest against the new government which exercised martial law on its citizens,[21] and became one of the key figures in the civilian activism.

[7] Living in Mizoram as a foreigner, he found it hard to make earning to support his family performing at various venues,[22] and then decided to start a YouTube channel.

[27] Sum then proceeded to make a music video "Tunah Erawh Zawng" [28] from which he was noticed by a Mizo producer, RPa Ralte [29] and got connected via YouTube comments.

In December 2022, Sum performed along with his band at Orange Festival in Dambuk, Arunachal Pradesh, India, and got featured in the Rolling Stone India with the description: "Myanmar-born, Mizoram artist Benjamin Sum – who had recently released his EP Out of the Blue – brought a raggedy pop-punk edge to the festival, matching the comedic heaviness of Green Day with jangly-pop and moving on to Radiohead-esque melancholy on "False Hope"."

[5] In India, one has to be a bona fide citizen to own a vehicle and should be registered using citizenship verifications such as electoral voter identity card and Aadhaar, among others.

Young Mizo Association (YMA) branch of Farkawn made a press statement that Sum was not born there,[44] proving that the certificate was forged.

[6] The news created a national furore and debate as other Burmese refugees were found to possess similar counterfeit documents.

[45][46] While fans sympathised and defended Sum,[6] YMA, as the largest organisation in Mizoram, intervened making a public statement that there had been a series of forgeries for Indian documents among the refugees.

[47][38] The controversy was feared to have a negative impact on how the refugees were received in Mizoram, such that the Central YMA urged the citizens not to take up further grudges against Sum and others who had fake documents.

[43][46] Sum himself never disclosed how he acquired the counterfeit documents,[39] and got "popular for all the wrong reasons", as North East Live reported.