it's probably because you're using the pellson practice rom. weird stuff happens sometimes with it, although i don't know the exact details

u can do 8-2 fpg but bbg saves more time over that. in any%, runners don't go for fpg because playing the level as fast as possible then doing fpg gives a 3 on the timer, which yields 3 fireworks, therefore wasting time instead of saving

yeah it's a Pellsson thing since you can't just magically restart the level on a normal rom.

tho that's possible in the vanilla game in 2 player mode if you go to 5-2, reveal the hidden vine, climb onto it and while going up, get killed by the hammer bro. Done correctly a vine will appear when the other player starts playing

also you can do fpg in 8-2 just like any level with a flag, its used in the Pacifist WR, its not used in normal any% since bbg saves more time