Wi-Fi & connectivity

[HappyAccidents]

this start yesterday but my Roku Premiere (4620 series) # is refusing to connect to wifi when I turn it on.
I’ve factory reset the item, rebooted my wifi, the whole shebang, but the device won’t connect to the wifi. every device I have is fine and has excellent connection. 
even the roku sees that it’s an excellent connection and the password’s right, but it won’t. connect. 

for reference, I have ATT fiber and the device is on the 2.4 channel. 

[DBDukes]

@HappyAccidents 

That device should also connect on 5 GHz band.

Here's what could be going on. Some ISPs that furnish the wireless setup have lately begun changing 2.4 GHz settings from b/g/n to g/n. Comcast is notorious, but others have done it too. Check that, if you can. If it's g/n, you'll get what you're getting. If it's already b/g/n, the issue is something else.