Jamal passed this ticket to me and I'll take care of this ticket. Hope this is OK.
Using View's GUI, yon can use the custom fields for primary order and post fields for secondary order. With secondary order custom fields are not supported at the moment. We do have feature request for this and we will try to add this feature in near future.
So, as I understand as a primary order, you want to use post_date and as secondary order you want to use your custom field. If this is correct - what if you try to use the view's filter wpv_filter_query and try to pass to multiple orderby prams on fly.
Can you please share problem URL and admin access details.
*** Please make a FULL BACKUP of your database and website.***
I would also eventually need to request temporary access (WP-Admin and FTP) to your site. Preferably to a test site where the problem has been replicated if possible in order to be of better help and check if some configurations might need to be changed.
I have set the next reply to private which means only you and I have access to it.