When I copy a quick filter (that returns values) to a page filter, it returns nothing.

[Mark]

Page filter (and working Quick filter) JQL: Labels = "Request"

[Nic Brough -Adaptavist-]

There is not enough context in your question, I am struggling to understand what you are saying.

You say you have a "quick filter" for "Labels = Request".  The JQL is clear and valid.  As a quick filter, this will be restricting the board it is on to issues with that label (from the full set of issues selected by the board filter).  But I do not know what you mean by "page filter"?

Also, what happens when you just run the same query as a plain search.

[Mark]

My mistake; I meant Board filter, not page.  Does this clear anything up?