Everything looks OK here. I suspect you are running into your 100 limit on the Query Elements component. You can set that higher or remove it all together with the ZUI -
An alternative way to do this gather by Category, then cast to Level to create branches of each level. This is less particular about Reference Level Parameters & more in line with Revit’s internal hierarchy.
Re_IssuesWithFilterByFLoorV1.gh (9.1 KB)