Boost in game tutorial prevents other boosts

The free XP boost the game shows for new players suddenly started being proposed for me (though I've been playing for several years).
It's probably because I entered the first story quests looking for an easy Spiderman target.

Anyway, I'm now forced to use it, but to do that, I have to replace the magic saga boost :-(

Anyway to get rid of this? I can't use the null event boosts like this.