I was set to 'Best Performance' and I just changed it to 'Good Performance and Compatibility'. Closed/re-opened the program. So far, I'm not having the previous issue when inserting symbols - now when I insert new symbols into the drawing; they appear immediately. It seems a little more "jerky" as I navigate around the screen or using the 'hand' tool. I'll continue to work and see if this fixes the other redraw issues.