Hitron 5GHz WiFi band disappearing each day when used with WiFi Extender


I have been using a Shaw Hitron modem/router for a number of years. However, the signal strength in the basement has never been very strong. To try to resolve this issue, in January, I purchased a Netgear Nighthawk AC1900 WiFi Range Extender (Model EX700). It has been set up to extend both the 2.4 GHz and 5 GHz bands. Shortly after setting this up I noticed that my 5 GHz network band name (both my original 5G and 5G_EXT names) would drop from being visible in all Mac & PC devices. I rebooted the Hitron router and the 5G network names would reappear for a few hours. I finally called Shaw support a few weeks ago and they couldn't trouble shoot the problem. They sent out a tech to replace the modem last week. However, by the next day the problem reoccurred with the replacement Hitron router. The only short term solution I have is to reboot the router. Has anybody else experienced this problem and have any long term solutions?

Need more help?