MPP Operations does not saved when I changed to select an existing operation. Thanks.

Hi  all,
 
Hope you are doing well during the quarantine!
Here is an urgent issue that need your help. In  MPP (Process Plan) module, we are trying to change to select an existing operation instead of  inserting an operation manually in MPP.  Since I updated the code as Screenshot below, the operation dialog works as I expected, but the Operations we selected does not save into database, of course it does not show in the mpp panel as well. please see the screenshots below.
Thanks very much.
 
Best regards,
Jen Li