DHCP is timing out during request on 2.4g wifi (5g works just fine on same router)

[toddler2015]

I have a 2.4g & 5g Wifi setup. The 2.4g SSID DHCP is timing out when trying to connect from several devices (tablets, Windows laptops, printers, etc). The 5g seems to be working just fine. There is just one unit serving up DHCP functionality on this LAN. I've checked to see if there are SSID conflicts with neighboring signals and cannot see any. The base router (serving DHCP function) is within 15 feet of the devices when it occurs. Any ideas of what else I can try?

 

[toddler2015]

An update on this one. I noticed that when digging into the security details that the 5GHz SSID was on mixed-mode WPA-PSK/WPA2-PSK and the 2.4GHz was purely WPA2-PSK. I set both up to be mixed mode and it worked. Not sure why this was causing any issues, but at least the DHCP isn't timing any longer.