No 5 GHz wifi networks detected

Question

I recently installed elementary OS Juno on my MacBook Pro 10,1 (Early 2013), dualbooting with MacOS. After initially not having any wifi at all after installation, I followed the instructions here which I usually do when installing new distros and successfully installed firmware-b43-installer.

However, I cannot detect any 5 GHz networks, only 2.4 GHz ones, despite having a compatible wifi card. 5 GHz networks are detected on MacOS, and were also detected on Ubuntu 18.10 which I used before installing elementary OS. I also updated the kernel to 4.19.66-041966-generic using UKUU. I also set /etc/default/crda to my country code which was suggested somewhere.

Some additional information about my system:

lspci -nn -d 14e4:

04:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM4331 802.11a/b/g/n [14e4:4331] (rev 02)

iwlist chan:

lo        no frequency information.

enx00e04c680a96  no frequency information.

wlp4s0b1  13 channels in total; available frequencies :
          Channel 01 : 2.412 GHz
          Channel 02 : 2.417 GHz
          Channel 03 : 2.422 GHz
          Channel 04 : 2.427 GHz
          Channel 05 : 2.432 GHz
          Channel 06 : 2.437 GHz
          Channel 07 : 2.442 GHz
          Channel 08 : 2.447 GHz
          Channel 09 : 2.452 GHz
          Channel 10 : 2.457 GHz
          Channel 11 : 2.462 GHz
          Channel 12 : 2.467 GHz
          Channel 13 : 2.472 GHz

I'm no expert but as far as I understand it, iwlist chan suggests the wifi card does not support 5 GHz (?), but as I wrote above I know for a fact that it does. Is there anything I can do to fix this problem? I need to be able to use my 5 GHz network since 2.4 GHz is unacceptably slow.

Thanks a lot for any help!

Answer 1

It seems like it was a driver issue. I already tried to sudo apt purge firmware-b43-installer and sudo apt install bcmwl-kernel-source, i.e. changing the drivers, which didn't solve the issue. However, I figured something might have gone wrong so I tried it again today. Purging the drivers caused the computer to crash, but then I did a hard reboot, installed the other drivers again using a wifi dongle, and now it worked.

Oddly enough, Ubuntu 18.10 and elementary OS 5 Juno don't use the same wifi drivers. Good to remember for the future.