What Firmware version is currently loaded?
What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?
Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended.
What brand wire and wireless devices are connected?
Does this happen with both wireless and wired devices?
What channel configurations are currently set on the router?
Be sure to disable any MAC Address randomizers on phones and pads while at home:
Try disabling the following and see:
Armor, Smart Parental Controls or Circle, Traffic Meter.
Has a factory reset and setup from scratch been performed since last FW update? A complete pull of the power adapters for a period of time after the factory reset then walk thru the setup wizard and setup from scratch with a wired PC and web browser. https://kb.netgear.com/22697/How-do-I-install-my-NETGEAR-router-using-the-router-web-interface
Do not load any saved backup configurations from file.
Recommend setting the default DHCP IP address pool range to the following after applying and a factory reset: 192.168.#.100 to 192.168.#.200.