I have enabled Smart Connect under wifi options in my AX6000. This merges 2.4GHz and 5GHz wifi frequencies. That was alright until I got the Brother MFC printer that works only on 2.4GHz. Now, printer still detects the network and connects to it but randomly my devices (phones, iPad and Macbook) loose printer connection and will not print. The printer still shows connected to Network but sitting dead.
So, I started 2.4GHz Guest WiFi on which just the printer can connect. I allowed Guest wifi to access internal network - assuming devices can now connect and take print but that didn't work. Mind that 2.4 GHz AP isolation is not enabled.
Even if I manually change the devices' wifi to connect to 2.4GHz guest network it still can't print. As you can see the Firmware is the latest one. I am certain that all such 2.4GHz 'only' supported devices will not be able to work/connect properly under "Smart Connect" mode. I don't intend to disable the functionality and create two SSIDs one for 2.4 and one for 5 - but I don't want manual separation of devices to connect to those frequencies.
Now, I can either return the printer or disable the Smart Connect (& let go my badwidth/speed benefits - the reason why we buy expensive routers) or do the wired connection with the router for which I have to do plenty of prep work.
** Printer has no network related issues. I have reset its network config. It connects successfuly to router. I can see DHCP giving IP address to printer as well. If I attach the cable - it works fine.