fid02 This is the answer I have received from the Revolut CSR when contacting via DM at Twitter/X:
"Sorry to hear about the issue you're experiencing with accessing your account. Currently, GrapheneOS is not supported. You can check the features supported by the web app here: https://help.revolut.com/help/more/revolut-web-app/what-features-are-supported-on-the-web-app/. Could you please try logging in using an Android or iOS device instead?"
I think GOS will not be supported, unfortunelly.