It seems like you've selected check box called "Read the entire restore point from source backup instead of synthesizing it from increments".
This way backup copy job is using the forward incremental backup method
, which means it would create .vibs until weekly full followed by 1 .vib appears.
So by the end of the week you should have 1 vbk and 6 vibs, then the job will create new vbk and completely delete previous chain on the next day when another .vib will be created. Thanks!