since updating an old app to meteor 2.6 (its now on meteor 2.13.x), some Meteor collections in the browser return an additional record, which is a copy of another record, but it’s _id is undefined.
On the server, everything is correct. I also don’t see that this additional document is published through the DDP connection.
I suspect its some bug in some old package we use, but its a bit hard to pin it down. I already ruled out subs-cache.
That’s why i ask the community whether someone has had a similar problem to narrow it down to a certain package.