I think you mean Cifas
That’s not what a Cifas marker is. There is description here What Is A Cifas Entry? | Jargon Buster | checkmyfile but the pertinent point is
A Cifas Entry (sometimes referred to as a Cifas Marker) on your Credit Report is a potential fraud warning, visible to prospective lenders to make them aware that you may be vulnerable to fraudulent attempts to take out credit in your name.
There is more info here Fraud Prevention for Individuals | Identity Theft Protection | Cifas
Additionally by the sounds of it the OP hasn’t been rejected for an account at this point. Given it’s a bank holiday that’s more likely an explanation for the delay than a Cifas marker at this point.