I have created a form with over 100 fields so I am using group fields. Within group fields, I am using 1 Image Upload field and 5 file upload fields. When the form is submitted it saves all the fields except 3 file fields (i.e. it saves 1 image upload field and only the 1st and 2nd file fields).
Note: I tried debugging before save and can see all 6 media fields have values in their respective $_FILE array variable.
Thanks for answering my question quickly, but I have already read the post you linked as an answer and also tried that.
1) my value for max_input_vars was 1000 and I have increased it to 10000 (before writing the question) checked using phpinfo command.
2) In my opinion Its not about max_input_vars because then I would have not seen the values of all (6) media files in $_FILES array populated after submit