Thank you for your asking.
Does the issue appear only on the stock camera and or on apps like Instagram as well? We suggest that you try clearing cache & storage of Camera (long press "Camera">App Info>Storage & memory>Clear cache/Clear storage). And then, if it happened on other apps, try to re-install apps and check again.
If the issue remain the same, kindly provide the information below so that we could better assist you.
1. Model Name: Settings>System>About phone
Refer to the link below to check the model name by model no. in the linkhttps://www.asus.com/support/FAQ/1014441/
2. Your current firmware version
Setting >System>About Phone>Software information
If you try to update to the latest version, does the issue still remain?
Furthermore, you could contact ASUS repair center in the country of your residence: https://www.asus.com/support/Service-Center-All-Countries/
If it is impossible to access the service center during Covid-19 period, please try Call us: https://www.asus.com/support/CallUs