Images not saving in ODK collect

1. What is the problem? Be very detailed.
i have developed a script with camera/Image capturing option but now images not saved in some devices..
the devices have free space upto 1gb..
i have also check the internal folder to verify images but there are no images saved in device..
Moreover Camera/Image is required and interview cannot complete interview without image capture...

2. What app or server are you using and on what device and operating system? Include version numbers.
ODK Collect and Aggregate Server

3. What you have you tried to fix the problem?

4. What steps can we take to reproduce the problem?
this issue is not occurred on all device, so unable to reproduce problem...
in addition the device make problem now, getting images before...

5. Anything else we should know or have? If you have a test form or screenshots or logs, attach below.

Do you get any error when you take a photo or just nothing happens?

nothing happen image capture success fully but not saved in device/ sync to server...

Is it visible in collect (under the buttons) or not as well?

yes on capture it shown on screen then we go forward