DynamoMEP Space.bypoint creates blue squares in Revit model-- what are these things?

Hello All,
I’m using Space.bypoint from the DynamoMEP package to create MEP spaces from the rooms in a linked architectural model. My sketch works fine, but it creates these blue dots at the insertion point of each space.

Even after I delete the spaces, the blue dots remain. What are these things, and how do I modify my sketch so they won’t be created? Sketch is as follows, it’s pretty simple:

Those are just points from the Dynamo preview. They don’t actually exist in Revit.

You can change your preview settings here:

Ah, thank you. I just noticed that if I close the file and re-open it, they go away.