Problems with network at home in cohousing (10 people)

Hey all, Im having troubles with my homenetwork, we are 10 people in cohousing using 1 or 2 devices per person.
Setup;
Telenet CV8560E model (not sending wifi connects using UTP with cisco WAP371. Cisco is sending on 5ghz.
At first the speed was good (40+ mps on laptop) but after a few hours it goes down till no internet possible. After power reset of Cisco the internet works again.
What could be the problem?