Loss of power in Alfa Romeo Giulietta 1.8 TBi 235 hp, clutch?

Hello dear people ☺️ Unfortunately, I've noticed a loss of power in my Giulietta this week. Sometimes it jerks briefly when accelerating, as if it doesn't have enough power. But what I've also noticed, and what I've read about, is that the car loses power when shifting from third to fourth gear, and doesn't deliver…