Ubuntu – 19.10: Thinkpad L13: Intel 9560: wifi interface suddenly disappeared

I've been running Ubuntu 19.10 for about three weeks on my new Thinkpad L13 Yoga. Been working great. Suddenly this evening, the wifi device is missing. Doesn't appear in the menu in the upper right. Not in Settings. Bluetooth is there, and I think it's provided by the same chip. The wifi here is the Intel 9560. I think the driver is iwl*. The kernel models appear to be running:

$ lsmod | fgrep iwl
iwlmvm 401408 0
mac80211 851968 1 iwlmvm
iwlwifi 348160 1 iwlmvm
cfg80211 712704 3 iwlmvm,iwlwifi,mac80211

Also,

lspci -knn | grep Net -A2
00:14.3 Network controller [0280]: Intel Corporation Device [8086:02f0]
Subsystem: Intel Corporation Device [8086:0030]
Kernel driver in use: iwlwifi

This L13 is set up for dual boot, and the wifi works normally in Windows 10.

I don't see that any updates were done between the time I used it this morning and this evening. I had it on wired ethernet this morning, though. I think the last time I used it on wifi was a couple of nights ago. But, I did have fwupd running, so maybe there was an update that I don't now about.

syslog gives messages:

Feb 20 09:02:21 yoga kernel: [    4.221887] iwlwifi 0000:00:14.3: Failed to start RT ucode: -110
Feb 20 09:02:21 yoga kernel: [    4.222207] iwlwifi 0000:00:14.3:Firmware not running - cannot dump error
Feb 20 09:02:21 yoga kernel: [    4.234862] iwlwifi 0000:00:14.3: Failed to run INIT ucode: -110

I've seen messages like this in searching for a solution, but nothing is working (in some cases, reports are older and their commands don't work). For example, I'd like to turn off power-saving mode for the wifi and I can't find a way to do that. There's even a kernel.org Bug 203891 that addresses this INIT ucode -110 and fixed it last year, but why would my wifi disappear a couple of days ago?

Thanks for your help.