If you put both laptops in one location, then what do you see? Do you have WiFi analyzer or something similar on your phone that lets you verify signal strength? 2.4Ghz has a longer wavelength and typically has a greater range in the house, so it wouldn’t surprise me if you see both signals in one location, but have some challenges connecting to the 5Ghz in a distance further away, but that doesn’t appear to be what you are experiencing. It could be a Network Interface Card (NIC) issue, depending on the age of the device. Many Internet of Things (IOT) devices only support 2.4Ghz. As a general rule, it is actually to your advantage to set the SSID for 2.4Ghz and 5Ghz to the same value. It makes roaming work more effectively.

I use Ookla speed test. (my cell is not currently being used for this) Both signals are NOT on any devise in any location. The laptop a few feet from the modem only has the 2.4Ghz signal (speed test download 42Mbps tops), and the laptop on the floor below (13 foot ceilings) far from the modem only has the 5Ghz signal (speed test download 116Mbps tops) As per your suggestion, I will, as planned, try both devices in the same place simultaneously. (my plan was both ‘far away’ downstairs where the 5G shows up)  (btw, I added the 5G SSID to my laptop that is near the modem and only gets the 2.4 SSID...still doesn’t show up) Anyway, thanks for taking the time to help me!  

Aha…on the laptop that only show the 2.4G SSID, I just checked ‘radio types supported’. there were only  802.11n, 802.11g and 802.11b network modes...so no 5G. Only 2.4G capability. I guess that explains why the 6G SSID doesn’t show up! Or is there a fix for that? Ciao!

802.11n protocol covers 5Ghz, but it may or may not be supported on your device. As far as a fix, the easiest way would be to us an external USB WiFi adapter. I’d stick with TP-Link, Netgear, or one of other major players. Looks like $15-20 unless you actually want something to set on the desk, which is probably overkill.

Thank you LoveMyLab!!!! The TP-Link USB AC1300 WiFi adapter, which I already had...after downloading the driver from their website (the CD that came with the adapter was either corrupted, or the CD/DVD drive, which I haven’t used in years, is kaput)...enabled me to connect with the 5G! How’d you know about that workaround?!!?! Again, THANK YOU!!!     .