I've got steps to help you successfully connect your HSBC bank to QuickBooks Online (QBO), Tomkensam.
To start, may I know if you encounter any error messages when connecting your bank to QBO? This information will help us provide you with an accurate solution.
Meanwhile, I recommend logging in to your HSBC bank website to check for ongoing maintenance or a temporary outage. You might also want to contact them to see if they've reported any known connection issues on their side.