my mac only works on 5G networks

AleVenOrt89 wrote:

about 1 week ago, my macbook pro doesn't connect to any 2.4 GHz network, only connect to 5G networks, anyone could help me with this issue?

Best regards.

2.4 GHz vs 5 GHz band on your local router...

5G Network—This is quite different. "5G Network" the fifth-generation technology standard for broadband

cellular networks, which cellular phone companies began deploying worldwide in 2019

5 GHz signals from your router allow faster communications. So the wireless signal at 5 GHz can travel 2-3 times faster than wireless signals at 2.4 GHz.

2.4 GHZ will travel further and penetrate more barriers.

Some Routers will 'automatically choose the best most appropriate wireless channel depending on local congestion.

This would be Simultaneous dual band routers ...

vs. manual dual band—this is where you have to choose one or the other manually.

See your Network in >System Settings/Preferences>Network and make some changes to suit you better.

ref: Recommended settings for Wi-Fi routers and access points

it is not say some aspect of your router failed...

You can shut down & restart: the modem, the router and the Mac— compare your results.

perhaps you meant to say your Mac only connects on the 5 GHz band, but not on the 2.4 GHz band ?

That could be due to USB interfrence:

Why do I have difficulty with Wi-Fi or Bluetooth devices when USB 3 devices are attached to my computer?

Some USB 3 devices can generate radio frequency interference that can cause Wi-Fi and Bluetooth devices operating in the 2.4GHz band to have issues communicating with your computer. Here are some tips to avoid this issue:

• If your USB device has a cable long enough that you can move the device, place it away from your Mac—and make sure not to place it behind your Mac, or near the hinge of its display. The antennas for Wi-Fi and Bluetooth are located there, and USB 3 devices placed there might interfere with your wireless connections.

• If you're using adapters or dongles on a Mac computer with Thunderbolt 3 (USB-C) ports, plug them into the front port on the left side of your Mac, or into the ports on the right side (if your computer has them). These ports are the farthest away from the antennas, making interference less likely.

• To avoid interference on the 2.4GHz band using Wi-Fi, try using the 5GHz band instead. You can change this on your wireless base station. Bluetooth always uses 2.4GHz, so this alternative isn't available for Bluetooth.

from:

About USB on Mac computers - Apple Support

Resolve Wi-Fi and Bluetooth issues caused by wireless interference

Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support