Ryanair like to ignore the regulator.
They quit their ADR after their last batch of self-inflicted problems with staff disputes (“We don’t like the ADR, they keep telling us we’re wrong!”) and still owe me £1k in rebooking costs which they have basically swerved for the time being. The CAA were supposed to be doing some kind of enforcement action to make them rejoin an ADR which they are obligated to be a part of but those wheels were already turning very slowly even before this happened.
In short: Don’t fly Ryanair. 