Hello Igunville47 and welcome to Apple Support Communities.
I see you are having an issue with being able to access your bank's website using Safari on an iPad.
One of the biggest changes when iPadOS split off from iOS was a full, desktop-class version of the Safari browser.
iPadOS - Apple
From what you are describing, it sounds like a specific issue between your bank's website and this new implementation of Safari. Outside of what you've already done, there is not a lot of direct Safari troubleshooting available. You should, of course, make sure you are running the most current version of iPadOS (13.4.1 at the time of this post).
Beyond that, as Safari is not an app that can be deleted and reinstalled, if you're already running the most up-to-date version of iPadOS, you may need to consider reinstalling iPadOS on your device. While this shouldn’t affect any data stored on the iPad, it would be a good idea to make sure you’ve got a backup in place: How to back up your iPhone, iPad, and iPod touch - Apple Support
Once you’ve successfully backed up your device, follow these steps to reinstall iPadOS, making sure to choose “Update” when prompted: If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support
If you take these steps and continue to get the same error only in Safari and only on the iPad, you'll want to let your bank know that there is a problem with their site and the latest implementation of Safari for the iPad.
Cheers.