Artifacts created with Dissolve > Aggregator

Hi Everyone,

 

 

I'm finding that artifacts are being introduced in polygons created using a dissolver then aggregator.

 

 

Here's the boundary I can get with the ArcGIS dissolve tool:

 

 

 

 

However, using an FME dissolver > aggregator, basing the grouping on the same fields, I get artifacts introduced at the borders of the input polygons:

 

 

 

A closer look at the polygons during an edit session:

 

 

 

We're not sure how these are getting created as our polygons have gone through the ArcGIS topology tools, and do not have gaps.

 

 

Any guidance appreciated!

 

 

Thank you!!!

 

 

-mb