I am using Quicken Premier 2018. One of my retirement accounts was providing some strange return numbers. It seems that the price history for one security is not complete. I tried to add a new price for that date (3/31/2012), but it won't show up. I've shut Quicken, shut down and restarted. Still not letting me enter a price for that date. On Morningstar, the quotes go back to 5/1/1992. When I list the holdings there's no price. I tried typing in the blank box, but the price disappears. Here's a shot of the holdings.

I'm not sure what to try next. Any help would be appreciated.