This has been a discussion on
http://pocketsense.blogspot.com/2018/08/new-version-available.html fairly recently. The trick is that you have to click "Read More" at the bottom of the page.
To summarize, make sure you have the latest version of PocketSense. Then Delete your Amex account, and add it back. To quote Ken from August 8, 2019,
"Make sure you're running the most current PocketSense and, when you add the account don't enter the account number, just the Amex login and password. It should then show you the Amex accounts associated with that ID. Select the line number of
the account you want to add. Don't type in the account number. If this isn't how it works for you then you're probably using an older version of PS."