Hi,
I use filters a lot (although we are still on v0.25 - but I guess they haven´t changed the filter behaviour) and I also have a lot of joins, but I have never experienced that behaviour or error message before.
The only thing that comes to my mind is that when I use filters as text filters, they look like your example. But field filters (where the variable type is a field filter and you then choose the database field belonging to that filter) my filters look like [[AND {{field}}]] (so without "field = {{field}}).
Could you try that?
It reminds me a bit of an issue another user had Unable to get field filters to return data in a MySQL query.
Let me know if it worked!