PixelMaster camera in Asus zenfone, how to remove strange limitation?

Question

Android

Asus' standard camera from the "factory" (PixelMaster Camera) has one strange limitation. For example, there you can choose the number of megapixels when shooting and the aspect ratio (6mp 16:9, etc.). But when choosing the maximum possible value of the MP, the aspect ratio is always 3:4. But if you install any other application, you can take pictures in the same amount of MP in 16:9 aspect ratio. Funny situation. How can I remove this "restriction", bypass it, etc.
My phone: Asus zenfone 5.