Archwiki say:
brcm80211
The kernel contains two built-in open-source drivers: brcmfmac for native FullMAC and brcmsmac for mac80211-based SoftMAC.
so if in your case brcmfmac is the one working good you can remove broadcom-wl also
sudo pacman -R broadcom-wl-dkms
so wl driver is removed and will not interrupt anymore…