If my prior suggestions didn’t help, you may want to implement my suggestion below.
I think it’s possible a wpa_supplicant update could be responsible for breaking your Broadcom wifi, as your symptoms seem similar to several instances where this has occurred in the past. You could always try downgrading wpa_supplicant , but it might be better to switch to using iwd instead. IWD tends to play better with some of the more flakey Broadcom wifi chips. Switching from wpa_supplicant to iwd may possibly fix your current issues.
How to replace wpa_supplicant with iwd:
With a text editor, create the required iwd configuration file for Network Manager:
/etc/NetworkManager/conf.d/wifi_backend.conf
With the following contents:
[device]
wifi.backend=iwd
Then, save the configuration file.
Next, Install and enable iwd, and mask wpa_supplicant:
sudo pacman -Syu iwd
systemctl stop NetworkManager
systemctl stop wpa_supplicant
systemctl mask wpa_supplicant
systemctl enable --now iwd.service
systemctl daemon-reload
systemctl start NetworkManager
A reboot could possibly be required, if restarting Network Manager doesn’t immediately correct your connectivity issues.
If switching to iwd is no improvement, then the changes can easily be reverted.
How to revert your changes and restore wpa_supplicant:
To restore wpa_supplicant, comment out the lines you created in /etc/NetworkManager/conf.d/wifi_backend.conf , as so:
#[device]
#wifi.backend=iwd
Save the changes, then execute:
systemctl stop NetworkManager
systemctl disable --now iwd.service
systemctl mask iwd.service
systemctl unmask wpa_supplicant
systemctl enable --now wpa_supplicant
systemctl daemon-reload
systemctl start NetworkManager
A reboot may be required afterwards to fully revert your changes.
IWD often improves reliability with Broadcom adapters, so it’s definitely worth giving it a try.
Good luck 