I appreciate the steps you've taken, Abu Husna.
The QBSE support team will be your number one resource for this type of issue.
I'd suggest reaching out to them so they can pull up your specific account in a private 1-on-1 setting and determine the reason why you can't reconnect your bank account within QuickBooks. You can reach out to them by following these steps:
- Go to the Assistant menu at the top.
- Type Talk to a human.
- Select from Message an agent or Get a callback.
In the meantime, I have here the articles that will help us bring in transactions into QuickBooks Self-Employed:
I'm always here to help if you have any additional banking concerns. Have a great day!