1. If the automatic screen brightness level function is turned on, it is recommended that you turn it off first.
2. If the flash screen appears after installing the software recently, it may be caused by the incompatibility between the software and the mobile phone. It is recommended that you uninstall the installed software and observe the comparison.
I suggest you restart your mobile phone to see if it has recovered.
If the above methods can't solve your problem, please back up important information such as mobile phone contacts and multimedia files, and bring the purchase invoice, warranty card and mobile phone to the OPPO customer service center for testing, and professional engineers will solve it for you.