I have some idea about how to retrieve your contact information. Let's start by resetting your app data as our first troubleshooting. Let's go to your account to see it.
Click Help on the navigation bar at the top.
Select Reset App Data.
Allow a moment for the process to complete, and then close the app.
Be sure to right-click the app and Run as Administrator when re-opening.
Here's how it looks like:
After resetting, go back and check your contacts again. If it doesn't work, I recommend doing a full reinstall of the program. The steps below will help you accomplish this:
The method for uninstalling the App varies based on which version of Windows you're using. Refer to the QBO Windows App Help Guide under the How do I uninstall? section.
Once uninstalled, you'll still need to delete the locally stored settings. Press the Windows key (⊞) on your keyboard, or click the icon (Start) on your screen and type %appdata% (including the percentage signs) in the search bar. Hit Enter.
Look for the QuickBooks folder. If you see a Roaming folder instead, open it first as the QuickBooks folder is contained within. Right-click and Delete the QuickBooks folder. This will be recreated when a fresh version of the app is installed.
Using the guide in Step 1, under the How do I install the app? section, re-install the QBO app based on the instructions for your version of Windows. It's recommended that you allow the program to be placed in the default installation directory (usually C:/ProgramFiles or ProgramFiles (x86)).