brodcom-wl-dkms might not work if you don’t have the appropriate linux headers for the kernel that you are using as the linux headers are an optional dependency for dkms
pamac install linux61-headers
From Arch Broadcom wiki:
" BCM4331 noticed to have problems with b43-firmware-classic.
Use b43-firmware for this card instead, or switch to
broadcom-wl mentioned below for a more stable experience."