Because the $161 number didn't include the early opening. The total run for Pikachu finished at $170.4 million. You might have to revise that down with the actuals, but the same goes for Endgame. Even if you want to make the point that those numbers don't count because it isn't the initial weekend launch, at that point it's a total semantics argument.
It's at $166,765,242
If you deduct the money made in those 3 territories from May 3-5 you get $161,810,156
So yea, it's clear Pikachu wasn't the number one movie. You can't add numbers made from the week before. And the Global numbers for End Game was just for the 3 day weekend.