First thing I'll recommend is to save a backup to revert back to just in case. You can find how to do so down below.
https://www.quicken.com/support/how-backup-or-restore-your-quicken-data
Next we'll try deactivating all of the accounts. You can do so by following the article listed down below.
https://www.quicken.com/support/deactivate-online-banking-services-quicken-account
Once all the accounts are deactivated go ahead and follow the article here on reconnecting the accounts.
https://help.quicken.com/pages/viewpage.action?pageId=3216277
Once you've had a chance see if you're able to get the account updating properly. Thanks,Quicken Francisco
This is located under File menu > File Operations > Validate & Repair option.
In the Validate File window that opens, click the top box to "validate file" and then click OK.
When the validation completes, a data log will open in Notepad, please let us know if any errors or issues are found/repaired, and when ready close and re-open Quicken.
Please let us know what you find!
-Quicken Tyka