More info according to [1]. At 13:10 Redsys (a payment Gateway) experienced an outage for hours[2]. At least around 18:00 it was resolved because I bought some groceries without any issue.

Sorry I only found information about this in Spanish.

[1] https://www.elmundo.es/economia/2023/11/18/6558baa1e4d4d8792...

[2] https://www.elmundo.es/economia/dinero-inversion/2023/11/19/...