Yep, seems to be working after a clean flash. Thanks OP and bkman08Appreciate the additional confirmation. I'll try another flash and see if I get any different results.
I did run into an issue during a separate dirty flash (while trying to nail down if my issue was related to the update or something else...I couldn't get replicate the brightness issue.) where I didn't push opengapps during the sideload of the latest update. Due to this, after booting up, I realized Google wasn't happy and went back to sideload opengapps. However this led me to a state where Play Services started having permission issues (seems to be common lately in other roms/experiences) where you can give it SMS permissions. Fortunately it's not System App Remover, you can remove Play Services (gms) and then reflash opengapps and restore proper functionality.
All other efforts (pm grant, freezing/clear storage/etc) did not help. Figured I'd mention this just in case anyone runs into it and don't want to clean flash the rom again just because you fubar'd your Gapps. I'm not sure why a reflash of opengapps didn't solve it or what causes SMS and PlayServices to not play together sometimes, but that worked for me.
(i flashed the previous version of Jag, installed opengapps and all my apps, no issues, flashed the latest Jag version, forgot Gapps, ran into issues with Gapps that were installed by me previously, flashed OGapps, no effect, uninstalled PlayServices, reflashed Gapps, profit)
The only thing left of the AutoBrightness issue is that the slider doesn't show the toggle for Auto Brightness. So adaptive brightness is working, but the toggle (with the A icon) isn't showing in the slider.