May I know which bank are you trying to connect with QuickBooks? This will let me know if there are any related reported issues with your bank.
On the other hand, error 355 usually occurs when there's a disrupted connection between QuickBooks and your bank. To resolve this, we can manually update the bank account to refresh the connection. I'll guide you how.
Web browsers collect cache (cookies) to save you time when loading repetitive data and images. These files can often become outdated or corrupted, causing issues like the one with your banking update. I recommend clearing the cache. I've included the links for all supported browsers that contain the steps for clearing the cache below.