5GHZ wifi is not showing on fresh install

I'm new to Linux. Apple stopped supporting my laptop (early 2011 Macbook pro 15) so I'm looking to join the linux family.

My laptop has a Broadcom BCM4331 2 band wireless card. It's this one...

03:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM4331 802.11a/b/g/n [14e4:4331] (rev 02)

I can access 2G and 5G bands fine on my OSX installation but on Linux I can only see the 2G option. I followed this guide...

Installing Broadcom Wireless Drivers

I followed answer 404, the lengthy one. On a previous installation I had 5G and 2g networks showing on Linux without a problem. But I had to re-install linux due to some issues and now I can only see the 2G option.

Does anyone know how to fix this? Would appreciate your help and guidance.

I had the same issue, so in my research I replaced Ubuntu with Debian and found https://wiki.debian.org/InstallingDebianOn/Apple/MacBookPro/9-2 While it is not your and my MacBookPro version, it does the trick

sudo apt install -y linux-headers-$(uname -r) && sudo apt install -y broadcom-sta-common broadcom-sta-source broadcom-sta-dkms

then reboot

reboot