Just sharing this as this was a fairly rare problem that required a manual hardware intervention.
After powering down my laptop, the wifi interface wouldn't come up. I found it to be hardware blocked in rfkill, presumably by the wifi button. However, when I pressed & released the wifi button, rfkill would show that software block change from yes to no. Which doesn't make any sense. I also went into the BIOS and disabled the WLAN button, but I still couldn't disable the hardware block After some Googlin' around, a find a forum thread in which someone else who had the same problem, physically removed the wifi card, cold booted, reinstalled it, cold booted and viola, the wifi interface was unblocked and working. I did this and it worked like a charm. Maybe this saves someone a few hours of grief some day. HP Elitebook running Debian 12 Bullseye. Sent with [Proton Mail](https://proton.me/) secure email.
