Those of in the UK with Santander accounts have been experiencing problems with the second stage, the one that requires a passcode and registration number. Thanks to the contributions of two 1Password users I believe we've found a way of working around the bad filling you're experiencing. Hopefully you find that the following helps.
- Download this 1PIF (1Password Interchange Format) file with a modified Santander Login item to your Desktop.
- If you're a Mac user, drag the 1PIF file to the 1Password icon in the macOS dock to import into the active vault. If All Vaults is active it will use the default vault for saving (Vaults tab in 1Password's preferences). If you're a Windows user select the menu option 1Password > Import, select the 1Password Interchange Format (1PIF) option and follow the prompts.
- Locate the imported Login item, it will be titled
Santander and will have a tag with the import date. Enter edit mode.
- Click the View Saved Form Details button if Mac or Web form details button if Windows to reveal three fields.
- Replace the placeholder values of each field with your real details and save.
You should find that this single Login item will allow you to fill your username on the first stage and then once you proceed to the second stage that it will correctly fill the passcode and registration number.