Wifi Connection Issues

[RV131826]

I am unable to connect 2 smart televisions, 1 laptop, 1 desktop, smart plugs and smart lights to my wifi network. Smart TVs and computers show an x on my Rogers wifi connection. Everything was working fine on Bell and when I made the initial switch to Rogers. Afterwards, plugs, lights started being unresponsive, TVs, and then computers. I purchased a usb WiFi for the laptop, it connected fine and the next time I tried it was the same as the the TVs showing an x on my wifi connection. I had to run cables from the modem to TVs to restore function...not sure if this is due to the new xfinity app that was downloaded, but there is little that I can change to get them to work.

My Android phone, ipad, and Alexa have no issues connecting...while everything else seems to be ignored by the modem.

I have searched posts and this seems to be an ongoing issue that Rogers techs offer little support for except to reboot the modem and to forget Connections and reconnect...which I have done several times.

Any real HELP would be appreciated.

***Edited Labels***

[LordDrakkon]

Is your WiFi split into 2? Having a 2.4GHz and a 5GHz can help a lot with troubleshooting because auto or a combined network can cause a lot of connectivity issues, especially with older devices. You might also want to refuce tue security on the 2.4GHz to WPA/WPA2 instead of WPA2/WPA3. Set the channel for each WiFi Network as well instead of leaving them on auto. Channels 6 is the most friendly for 2.4GHz but 3 or 9 should be fine as well.

[RV131826]

My Wi-Fi is split. Scanning shows 2 separate connections.
I have tried changing security to WPA2 through the Xfinity App, however while I can make the change I am unable to update it.
I tried logging into the modem directly but options to change WPA3 to WPA2 are whited out and not accessible.
I restarted the modem, unplugged the modem several times all to no avail. My cell phone, iPad, Echo speakers are connected.
Smart TVs, laptops and desktops show a small x in a circle, lower left of the connection.
They try to connect but are ignored by the modem.
I tried forgetting the connections and rescanning...nothing changes.
My last option, it would seem, is to delete the App, do a factory reset on the modem Gateway and start trying to connect everything all over.