I accidentally found a glitch that allows you to skip from 1 to 4 missions and be immediately on the last mission (On the top oh the world). Performed by exiting and re-entering from Delivery Waifu

I am not 100% sure but that might be because you've completed the game to the mission 5 before and it just loaded your best save so basically it's not the same run.

yes, after all, you are right, it depends on the past completed the game

because after completing the mission and reuse, it was already moved to the 1st mission

then the question is closed