Some apps work and some don’t

[Bunyipyeti]

Between 11pm to 8am and 3pm to 5pm a few mostly gaming apps are unable to get a wifi connection to load when I am at home. Other apps including news apps and YouTube work fine. The apps work on cellular network fine during this time and also work fine at other houses on wifi during these hours. I have checked parental controls on wifi router and that is off. Also have restarted/ rebooted, iPads and wifi. It’s like there is a modem parental control but not sure how to deactivate it?

 Thanks for any help

[cf4]

Try changing the both IPv4 and IPv6 DNS in the modem's advanced > Local Network settings. Save settings and disconnect and  reconnect your device.