I created several .bib files with different formats by right clicking the collection, choosing Export Collection, and selecting the 'Keep updated' option. In case it matters, the collection was in a shared library. Once I decided on the .bib format I wanted to keep, I deleted the rest. However, I've now deleted them several times as they keep showing back up. I can force them to repopulate by editing a field of an item in the subcollection which triggers the updating of linked .bib files.

Please help me stop Zotero from populating these unwanted .bib files.