Why does shape area/length fields get changed for local copy editing of feature layer?

[RobCahalan]

I am using ArcMap 10.5.1 and ArcGIS Online. I have published a layer in ArcMap to a hosted feature layer with feature access. Once published, the feature layer setting show that edit and sync are enabled. When the feature layer is brought into ArcMap and I "Create a copy for local editing," additional Shape_Length/Area fields are created which precludes me from editing feature geometries. I do not have this issue when trying to edit in ArcGIS Pro, but I have some end users making edits that do not use Pro yet. When I try to cut a feature in ArcMap I receive the following error:

I have traced the issue back to the Shape attributes.

The SHAPE_Length/Area fields look like this in the original file geodatabase (notice SHAPE is all caps):

The Shape_Length/Area fields look like this in the hosted feature service (notice no caps and double underscore):

The Shape_Length/Area field look like this in the local copy:

If the Shape__Area and Shape__Length fields are deleted in the local copy, the geometry is able to be edited and synced back to AGOL.

Is there a problem in the way that I am publishing the data that is causing the issues with the Shape fields? 

[JacobHorstkamp]

Have you figured this out? I'm having a similar issue.

[RobCahalan]

I have not...at this point I am typically doing edits in ArcMap...

[David_Brooks]

@RobCahalan im also experiencing this. It seems like the system default for geodatases is a single underscore, but in a postgresql database like in AGOL or enterprise, its a double underscore. it's actually very annoying because you cant set any symbology, popups or labels based on this field, prior to publish from FGDB in Pro up to AGOL. you have to then sort your symbology in the web map, which is sub-optimal