DIXF import is failing for extension entity

Hi all,

I have an extension of the standard entity Customers V3 wherein I had added some relations as well as custom code. On exporting I was getting an error:

I removed all customizations and extensions, after doing a build, sync and all entity refresh I am still getting this issue. I tried creating a duplicate of this entity and when exporting it the entity exports fine - also please note I have verified in view level in SQL both the entities have same exact number of records and the duplicate records are present in both entities. Could anyone please suggest a different approach to analyze and rectify this.

Thanks in advance!