Can't delete document or update attribute

I recently added a new required string attribute called author_id to a collection, and then tried to use the cloud GUI to delete old documents that didn't have anything entered for this attribute. However, just one of those documents refuses to delete: when I try to delete it, I get an error that the document is invalid because it has no author_id.

I tried editing the author_id attribute itself to no longer be required, but the problem persists even when this attribute is no longer flagged as required. Also, I tried manually entering something for that document's author_id though the GUI, but even while I'm trying to input an author id, it won't let me save because author_id is missing and therefore the document is invalid!

PS, I'm using the beta "relationships" feature in this collection, so idk if that could be the cause for any wonkiness?

In case you need to investigate anything from your side, here's the project IDs: project ID: artfork (I set this one manually instead of the auto generated one) database ID: 67b19543001981d2c08a collection ID: 67b195c40035ca813254