Got a new card from Amazon, now everything is working. This is the second time I'm having this issue - had it once when the laptop was on warranty, so Dell replaced it (probably, they never tell what they do). Why does the card keep breaking? Will this continue to happen every 2-3 years? This is really annoying. But, thanks to Dell, I now know how to change cards, lol.
My wireless card stopped working. 1) In BIOS, both Wifi and Bluetooth are connected. Everything else there appears to be "default" - the switches for both are on, and the functions are enabled which makes logical sense. 2) All needed drivers are present in /lib/firmware. (When the card stopped working, I reinstalled the entire OS (Fedora), then I also removed and reinstalled the 'firmware-linux' package. I tried to use the driver version from the manufacturer's site as well.)  3) I tried to detect the card with Pop OS (live USB) and the iwctl tool on Arch installer. None of this worked either, so it's clearly not an OS problem... 4) Some people had luck removing the card, and then inserting it back. So I pulled out the AC power jack, removed the back cover (the laptop is not on warranty), disconnected the battery, then pushed and held the power button for a few seconds, pulled out the card and reinserted it. All to to avail. Is there anything else that can be tried (other than installing a new card, or using a USB dongle)?  I'll likely try to a new card later, if nothing works (I'm not in a hurry). Any advice is appreciated. Thanks!
Inspiron 7786 - Wireless card AC9560 is not recognized by OS (but is seen by 
BIOS)