That’s odd.
I’ve never used some of the other smaller legacy banks (TSB, Co-op, Nationwide.), but both Barclays and Natwest works fine.
I assume it’s due to Wirecard being based out of Germany (Eurozone, EUR.), which is why some legacy banks might confuse Revolut’s new Wirecard-issued cards (As opposed to PaySafe, which is based out of the UK, hence GBP.) as having the Euro as the base currency.