If none of these suggestions work, I recommend contacting our QBO Care Team. They have tools to help configure the connection of your accounts. Then, walk you through the steps on how to get them up and running.
Click on the Help icon at the top to open the QB Assistant window.
From there, tap the Talk to a human menu and enter the issue/topic.
Next, hit I still need a human button to display the QB Assistant pop-up.
Click the Contact us link.
Follow the on-screen instructions to complete the process.
Select Message an agent for real-time assistance or Get a callback.
Since you were unable to get this issue resolve when syncing with Fifth Third Bank transactions to QuickBooks, I'd recommend contacting your bank to verify any news. It could be that the bank is having a system maintenance update on their end.
If there's no issue with your bank, I encourage you to reach our Care Support Team to investigate this further. There they have tools and create a case for this issue and submit it to our product engineers to work and fix it thoroughly. You can follow the steps provided by my colleague, @Rasa-LilaM, on how to contact them.
For additional reference, you can check these articles about the available hours of our chat and phone assistance: