Auto brightness of old (directly linked to a light sensor) no longer exists. It is now Adaptive Brightness, which uses Google AI to decide what...
check out https://forums.oneplus.com/threads/smart-lock-doesnt-show-any-options.626145/ - its in the 5 board, but looks the same.
Do you have a SIM from another country in there/have you ever? The disable is picked up from the SIM source country.
you have enabled Select to Speak in Accessibility settings.