Tester appears to be missing some Nulls

I have an SDE Geodatabase (ArcObjects) data source and want to filter out all features with no name.

I've used a tester with a test for 'has a value'.

I've also tried testing for 'not null AND not emtpy string'

I've also tried using a NullAttributeMapper and mapping Nulls to some value and testing for that.

Whatever I do, 49 'Nulls' make it through to the output, even if I add more testers. Workspace obviously doesn't think these are Null/empty, but the inspector reports them as <null> after running the workspace.

I can just manually delete these from my output later, but if anyone can shed some light on what is happening here, I'd appreciate it.

I'm using Workbench 2016.1.1

edit:

if I query the oracle view in the geodatabase

select name, road_type from PLAN.roads_src where name is not null order by name;

I get a number of results with <NULL> for name.

So it appears FME is doing exactly what it is asked. So I guess not an FME issue, but still if anyone has some idea what is going on here...