Wi-fi shows connected on devices but internet stops working until wi-fi is disabled/re-enabled on those devices. Rebooting the T3200M modem doesn't solve the issue. Have tried repositioning it too, but it was fine before so I don't think it's interference. Seems to have started after Apple OS/iOS upgrades and is happening with increasing frequency. We started having wi-fi issues months back with our Apple TV, until I connected it directly to the modem to bypass wi-fi. Windows laptop doesn't seem to have the issue. Contacting TELUS support is such a soul destroying prospect.
Try disabling Smart Steering if it's enabled. Use different SSID's for the different bands and see if you have better luck with one band or another. 5Ghz gives you better speed but shorter distance, while 2.4Ghz has a wider coverage but slower speeds.
This Youtube video can step you through the process:
I had constant issues with my iPhone dropping out. It would connect to the WiFi when I started it up, but would drop out after an hour or so. Turning on the Airplane mode and back off again would restore the connection for another hour or so. I finally disabled SmartSteering as @FuzzyLogic suggested, and forced my iPhone to connect to the 2.5G network. On 2.4G it stays connected all day with no problems.
Is your wifi router in the basement where it can't see the neighbours' routers, or is it on the main floor? A router downstairs can't see what other frequencies are being used outside. There's an app that you can use on Chromebook or android devices that can tell you which channels are being used by which SSID's if you have one of those devices available to you. If your channels are set to auto and the router is in the basement, that will cause this exact problem.