Tentative Snap stops working

When I first open Geopak drainage, I am able to tentative snap to a point where I would like to place a note. For example, I need to adjust an inlet top, so I am snapping a new manhole top to the center of the existing one. 

This works fine for a few nodes, then all of a sudden, I can no longer maintain the snap. I tentative snap to the center, it appears to take it, but then loses the snap, and goes back to my cursor position.

Is there anything I can do to stop this? It takes a long time to open and close my Drainage project every time. We even moved our drainage project, gpk, and preferences to a local server to try and speed things up. All of our project files are on a remote server.

Thanks