@Arun_Rawat Try resetting the router to its factory defaults to see if that can resolve the issue. Press and hold the reset button for more than 5 seconds (use toothpick or paperclip):

@Thirith Sometimes disabling Smart Connect feature improves your wireless experience like in your case. There's nothing wrong to have two SSIDs - one for 2.4GHz band and one for 5GHz band. What I...

@SaiGer To be able to receive IP addresses on VLANs other than the default VLAN 1, your router should be VLAN capable. I don't believe that Bell Home Hub 3000 is VLANs capable device. Here are some...

@Thirith Make sure you're with the latest FW for your C2300. If you have to, search for the latest FW release for your FW region and HW version. Here's how to determine that. You can scan for...

@ColinChambers59 Check this thread for details. You can setup the tp link ac750 extender as a regular extender to the existing Deco mesh (whether with the same or different SSID).

@Thirith From your description, probably your C2300 wireless radio is defective. You may contact your local TP-Link support to be advised on this issue.