Custom Invoice Id not searchable

Hello,
There seem to be bug with the custom invoice id. Or am i not understanding properly. I created a invoice and using toggle advanced button, i set a custom invoice id. Once i saved the invoice. Till now everything thing works as it should.

But when i go to search from the front end being the user (who should receive the invoice). i searched for the custom invoice number that i set. Then it just won’t show up. It show 404 error. and also in the admin area in search filter and filter by invoice id too. But if i searched the invoice id that was automatically generated by the plugin which is also at the bottom of the custom invoice id in ” View all invoice ” Page then it will show me the invoice! Why can’t i searched the invoice with the custom id that i set when i created the invoice?

I am currently using this plugin in my own custom theme and i am sure there is nothing with my theme since i tried this in default twenty fifteen theme too. Searched in forum but couldn’t be found any topic related to this. How come i am the only one having this issue. Could you please let me know why i can’t searched the invoice using custom invoice id.

Or am i missing some explanation here about the custom invoice id. Plz.

Cheers

https://wordpress.org/plugins/wp-invoice/