Sound was previously working in 16.04, now stopped

This is an install that was upgraded from 14.04 to 16.04. It's also a dual boot (with Windows 10) using GRUB. Originally on 14.04 I had to use an ALSA daily build to get sound working (https://askubuntu.com/questions/672187/no-audio-output-devices-detected-in-new-computer-build-with-skylake-z170-mothe). When I upgraded to 16.04 I uninstalled that daily build .deb as it was no longer necessary. But just this past week the sound suddenly stopped - not sure if a package or kernel upgrade caused it or what.

Based on my previous experience the first thing I tried was installing an ALSA daily build. I tried both oem-audio-hda-daily-dkms_0.201708220416~ubuntu16.04.1_all.deb and oem-audio-hda-daily-lts-xenial-dkms_0.201708220446~ubuntu16.04.1_all.deb (from this page https://code.launchpad.net/~ubuntu-audio-dev/+archive/ubuntu/alsa-daily/+packages) without any luck.

After that I went through the troubleshooting steps here: https://help.ubuntu.com/community/SoundTroubleshooting

and here: https://help.ubuntu.com/community/SoundTroubleshootingProcedure

Including obvious steps like "Refreshing/reinstalling the drivers," trying all the different audio ports, making sure the right output device is selected (Intel Corporation Sunrise Point-H HD Audio) and not muted / volume cranked way up, trying my headphones and speakers (different hardware), etc., but none of the suggestions has fixed it. I know it's not a hardware problem because when I boot into Windows the sound works fine.

When I run pavucontrol the audio meter correctly shows when my applications are playing audio, and detects when I've plugged my speaker cable in or not (when it's not plugged in the analog options disappear and S/PDIF shows up): https://imgur.com/a/MKf13

I'm not sure what else to try other than a fresh 16.04 install... hopefully that can be avoided. Here is my also-info.txt debug info: https://gist.github.com/abevoelker/a79023c536c682543f6e2ded03ae9cc7#file-alsa-info-txt

And here is the "Step 4" debug info: https://gist.github.com/abevoelker/a79023c536c682543f6e2ded03ae9cc7#file-step4-txt