In CorelDraw, there is an option Arrange\Join (X5) or Arrange\Combine (X4 and previous) or Ctrl-L

This joins small breaks in lines.

In the inkscape, the equivalent function seems to be "union". However, this doesn't work most of the time and the drawing is completely changed.

Is there a more similar function to the CorelDraw equivalents?

Union takes two objects and merges them into one. Are you sure you're not looking for Node tool, where you can join breaks between nodes? Select node tool and look at the buttons on the toolbar.

Thanks for the quick reply! In CorelDraw I just select a bunch of nodes and join them all together into 1 path.

Inkscape it appears I could only grab each node and join them individually?

These DXF drawings I import are maybe .0001mm off or something and should just automatically be closed...

I've never used CorelDraw, but in Inkscape if you have nodes it means they're already on a path, and you can only join end nodes.

Are you saying that you get open paths when they should be closed?