I looked into our system and didn't find any similar issues. These kinds of errors are sometimes caused by stored cache files from the frequently accessed pages such as QuickBooks. We can isolate it by logging in to QuickBooks using a private browser. To open one, you can use these keyboard shortcuts:
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Safari: Command + Option + P
Then, check the Banking page if the account was successfully connected and you're not prompted with the error. If it works as expected, you can switch back to the main browser and clear the cache. Other supported browsers can help you get rid of these kinds of issues.
Feel free to use these articles that will help you handle bank downloaded transactions: