After a couple of successful prints (except for some sticking problems like a lot of users) the amount of filament coming out of the nozzle is much less.
Normally, a few second before printing the nozzle start to melt some filament and then hit the bed but today it wouldn’t do it anymore.
So I checked the gears and everything seems normal.
I tried to force the filament manually (while pressing the “feeding button”) and it comes out normally - which tells me that the nozzle is not clogged.
It seems that the gears are not pulling the filament consistently.