How to enforce submission only one time to a list

Dear Team,

I want to enforce users to submit the data to the list, i have successfully implemented the solution using below article/post. But i have small problem, if you have already submitted once and you delete record from list and try to submit the item, still it says you have already submitted once. 

https://community.nintex.com/t5/Community-Blogs/Enforce-submission-only-once/ba-p/82126

Any suggestions would be highly appreciated.

Thanks in advance.

Regards,