Simply, the goal was chalked off because a Palace player was standing too close to the Chelsea wall.
Referee Darren England made an announcement to the crowd to explain the decision.
He said: “After review, away number six is less than one metre away from the wall as the shot is taken. Therefore, it’s an indirect free-kick and a disallowed goal.”
The International Football Association Board’s Law 13 states that when three or more defending team players form a wall, all attacking players must remain at least one metre from the wall until the ball is in play.
This rule was introduced to the laws of the game in 2019-20.
The explanation at the time was that “attackers standing very close to, or in, the defensive ‘wall’ at a free-kick often cause management problems and waste time”.
It continued: “There is no legitimate tactical justification for attackers to be in the ‘wall’ and their presence often damages the image of the game.”
And so Eze’s goal was disallowed.