We tried to submit crew members to our film but they never appeared on the site.

Sorry to hear. You should be able to locate and check the status of the submissions via the new experimental tracking system at https://contribute.imdb.com/contributions/history ... does this help? 

Please let us know the 18-digit contribution IDs of the rejected submissions. 

Thanks for your reply.

Here is the ID: 190112-151433-287000

For eg. our lead  producer has been declined, whos name is on the movie poster.

This new tracking looks very helpful. For many times the tracking said, there is not enough evidence.

Can you tell us how should we submit our crewmembers to have enough evidence?

Hi Ester -

Thanks for posting the screen grab.  The producer credit has now been approved and should be listed on the title page shortly.  Cheers!