After finishing 39th in the individual event, 27th in the sprint, and making a remarkable comeback in the pursuit (8th place), he won the world title in the young men's relay, alongside Jorgen Krogsaeter and Sivert Guttorm Bakken.

A few weeks later, he stepped onto his first podium after the mixed relay (with Karoline Knotten, Eline Grue, and Frederik Gjesbakk, securing third place).

In the subsequent season, Sørum returned to the IBU Cup competition after the 2020 Junior World Championships in Lenzerheide, winning new medals - silver in the individual and gold in the sprint.

[4] He then claimed his first individual podium on the senior circuit (IBU Cup) by winning the super sprint in Martell, surpassing German biathlete Simon Schempp.

He securing victory with Endre Strømsheim, Johannes Dale-Skjevdal, and Vetle Sjåstad Christiansen, stepping onto the World Cup podium for the first time in his debut stage.