I have similar problems with you. When I killed him, I killed Boss Sunflower, and I was about to get into the elevator. It's stuck in that place, and it's no use hitting it.

So it's better to buy a plate. And 3 is not as fun as 2, which is strange. It almost killed me, but I found two bugs. The first level, BOSS can't hit him in the middle of the head, it will hurt his blood. When he hits Sunflower BOSS again, he walks up for a while, and there are vines of 1, among which there is a certain chance that he won't open it for you, which will hurt his blood.