How about Arena? Or Ranked Battle? Or Treasure hunt? Those c*l be done 5 times as well and I suspected you collected the rewards for them. The weekly missions does not directly disappear after 3 times while showing that you've also collected your 5 weekly mission rewards.

What I suspect is that you've already collected all the 5 rewards and your GNW was the 6th, but it's too late, you already collected 5 others. It had happened to me before in the 1st week this event was launched. So remember to collect d those S inches first in future. You can click to change it to 9 Tails and Win in Matsuri to make sure you finish them on Monday.