Working time vs activity's responsible/pool of ressources

Good morning,

i have noticed that when you assign a pool of ressources to an activity with x days, the working time spreadsheet gets wrong when the responsible of the activity is within the pool of ressources.

It seems that if the responsbile of the activity is within the pool, it does not take it into account and create automatically a new line on the assignation for the responsible.

Therefore, the calculation gets wrong as I want to assign X days to the pool and that's it. I don't want that line to interfere with the assignation.