A search shows me this issue has gone on for many years.
I am running Version 5 SR14 64-bit on a Win10 laptop.
I have Project selected because there are objects I want to snap to but I want the new curves all in the construction plane. Arcs and circles display as a dashed linetype. I can fix them with Rebuild but why should I have to? This doesn’t happen in Project isn’t selected.
A picture of what’s happening might help, but here are a few idea’s.
I would take screenshot of your OpenGL page under “Tools: Options: View: OpenGL” and post it here. Verify you have the newest graphic card drivers. Windows update usually doesn’t get the current driver installed. Although it will tell you it’s the most up to date driver when it’s not.
Are you just drawing on the default layer? If you highlight the line while it’s dashed and look under properties and linetype is that set to continuous? Perhaps the layer being drawn on isn’t the same as the one that the rebuild curve is being created on and the line types are set different?