After the last update, two things happened:
1. The timeout on my display switches itself back to 30 second , every single time I set it to 2 minutes.
2. My Always on Display is off. And it's not only OFF, but it's not even avaliable in the settings (it's greyed out).
I'm so tired of these kinds of things. I'm starting to wonder if I should just hunt down a flip phone.
Have you tried wiping the cache partition on your device?