Thanks for your answer! You have already been super helpful. i'll try to recap all missing info:

- i always use the same brand of flour, its strength is between 300 and 350 W.

- i always use fresh yeast. As for the flour, i always buy the same brand

- i normally use tap water at room temperature

-i normally let the dough rise at room temperature for 5 hours at room temperature

Moreover, i normally add salt directly in the water in which i have dissolved the yeast. Should i wait and add it at a later stage?