After the general health code is turned on, the system will automatically adjust the brightness. If not, you can turn up the brightness of your mobile phone yourself.
It may be because the application itself adjusted the screen brightness. Permission of brightness level is open to third-party applications, and some applications (such as video players, readers, payment applications, etc. ) can manage brightness. In addition, in order to reduce the power consumption of the mobile phone, the system appropriately reduces the brightness for some application scenarios.