Thanks for joining this thread, Bren123456.

I want to make sure you're able to connect your bank to QuickBooks Online.

Just to verify, were you able to try opening QBO in a private/incognito window and/or clear the browser cache? If so and the problem is persisting, I recommend contacting the QuickBooks Online Support Team. Agents have specialized tools, like the ability to share your screen, to take a closer look at what could be causing this issue. They would also be able to get this issue escalated for you if need be. 

You can review the steps to contact the team by visiting this link: Get help with QuickBooks products and services.

Please feel free to reach back out if you have any other questions. I'll be here to help in any way that I can.