I am using Zonal Statistics as Table to obtain the Max height from a DEM for each polygon (then Joined to the polygons). For some reason, a lot of the polygons get NULL returned. All the polygons returning Null appear to be between 1 - 4 cells in size (given the DEM scale). Other same sized polygons are however returning the expected result. 154 out of 3131 polygons have NULL values
I have used the Identify tool to check that I do have non-null values in the underlying DEM for a bunch of these.
The problem appears to be the FID is not being created for the Zonal Statistics table for some polygons. I have checked a couple of other small polygons and the values obtained from Zonal Statistics appear correct. What should I be looking for/testing? How can I correct this?
I am using ArcGIS Desktop v10.6 with Advanced License.