Thanks for providing the error you encountered, Juan. I understand the significance of showing your bank transactions in the QuickBooks Online (QBO) account. I'm here to help you out.
In the meantime, we can manually update the connection between your bank and QBO account. See the steps below:
Click the Banking menu.
Go to Bank Feeds.
Select Update in the upper right.
If the issue persists, let's access your account through an incognito window to rule out the possibility of a webpage issue. You can refer to these shortcut keys to open an incognito window in all supported browsers:
Chrome: Ctrl + Shift + N
Firefox: Ctrl + Shift + P
Safari: Command + Shift + N
If it works, switch back to your regular browser. Then, clear its cache. This way, you can access QuickBooks with a clean slate. You can also use a different supported one.
To ensure we address this matter effectively, may I know the name of your bank account? This way, I can gather enough details and check for possible investigations.