Form ranks Minutemen/ Sanctuary hills

[SiGuN]

Hello ive been stuck for ages in the quest form ranks... So it says i need to recruit more settlements to the minutemen i already brought 5 to sanctuary hillls. i have a total of 13 there if not mistaken. My stats i think are pretty good i have 40 food 40 water 60 defense 30 power and overall 80 happiness and i cant get more people to come..

If someone could explain what am i doing wrong would be nice.

Thanks in advance