The match timeline
Argentina's opening match at the 2022 men's World Cup ended in a 2–1 defeat to Saudi Arabia. Lionel Messi converted a tenth-minute penalty. After halftime, Saleh Al Shehri equalized in the 48th minute and Salem Al Dawsari scored the winner in the 53rd.
FIFA's match report also records three Argentina goals disallowed for offside before the interval. Those decisions explain why the official halftime advantage remained one goal despite Argentina repeatedly finding the net. A disallowed attempt is not part of the final scoring total.
Source [1]A group result is not a tournament verdict
The result was a major reversal within the match: Saudi Arabia turned a halftime deficit into victory within the opening minutes of the second half. It was nevertheless one group-stage fixture, not an elimination match. Losing it did not by itself end Argentina's tournament.
Argentina later reached the final by defeating Croatia 3–0. Reading those matches together gives a more useful account than treating the opening upset as the conclusion of the campaign. For the technology behind some offside checks in Qatar, the linked guide explains the division between tracking software and the officials' decisions.
Source [1]