Bullet games appear while opening book is set to blitz & classical

Sometimes, bullet games appear in the opening book even if only blitz and classical are selected. For example, if you go to the following position: en.lichess.org/HBe3td6A/black#23 and set the opening book to Lichess, 2000-2200-2500, blitz-classical, the game above will appear, while 1/4+1 is clearly bullet.

Nobody seems to be interested in this rather annoying issue?

It's even worse now. Even in the initial position, the top games are all bullet games even though bullet is not selected.

It seems as though only recent games are wrongly placed. When I select bullet games as well, I get other top games than if I don't, even though all results are bullet games.