reference with b even though a was removed

Hi,

I had duplicate references in my document, because I merged multiple documents and the references weren’t up to date everywhere. I brought all references up to date and then via the “Find duplicates” removed one. This worked in 90% of the cases.

However, in one case I still get author et al. (2012b) even though there is no other reference by that author in my database. I have another one from 2015 by the same first author, but it is a sole authored work and it is displayed correctly.

How can I convince endnote that the b is unnecessary?

I have tried various things I read online like exporting it to a traveling library, changing style, but nothing works so far. 

Any suggestions?

Thanks!

Solved: Edit&Manage citations showed that this reference was still in a travelling library and in my library, hence endnote thought it was there twice.