Some problems using rapid bolts with crossbow and mercenary

Hi to all ,

I'm new to PoE2, I'm at level 25 and I've managed to beat the first Colossus in Act II. Given that I play with an Xbox controller connected to my Rog Ally X (which apparently doesn't allow you to play this game on the go), when I press RT, it always takes a fraction of a second before the crossbow starts firing. I increased the number of projectiles to 52 with a perk, am I the only one noticing this problem?