I will try my best to explain this my camera wouldnt switch to selfie mode or record a video when i touched screen to either record a video or switch to selfie mode it would just take a picture to fix my camera. i had enlarged my widgets i think thats what they are called and thats when camera stopped working went back and made widgets smaller and camera works again i hope this makes sense .
Apparently adjusting the system font display size from anything other than "Default" causes this issue. I hadthe same problem and lost control of cam flip and video recording. When i reverted back to "Default" font size both controls started working again.