GL702ZC - Screen Brightness doesn't survive reboots since last update

About 2 days ago I did a full update (stable). However, after update I noticed the screen brightness setting doesn’t survive reboots anymore (it was working before update). It’s now always set to 100% upon system startup, which is too bright. I can still manually tone it down to 50% via FN+F5 combination though.

I first observed this issue right after the update, before installing the 5.8 kernel (I was on 5.7). Installing the 5.8 kernel doesn’t solve this either, so the issue is not kernel-related.