Sorry to hear you're encountering issue while using Moneydance. Moneydance 2017.8 (1693) is now available on our website here. This new build of Moneydance should address the problem. Can you try updating to the new version and let me know how you get on?
Manually updating has always been problematic. Make sure that you update the dated rate and update the "current value" at the top. When entering data be sure to type "enter" so that the cursor moves to the next line and the data is actually recorded.
That is all I got. Possibly Ian O. can give more help or get the developer to fix this.