Paul, can you clarify:

When I try to drag the route away from EV1 at a certain point the route will not move.

You've added Viapoint 1 so your route has 'moved' from the EV1 route? However, we can see that the options of where we can place that viapoint are limited. 

It's not obvious with the route displayed on the map but remove the route and you can see that the map is clearly showing another bike route - the Coastal Route. That information is also available by clicking on the VP1:

In other words, when 'Routes' is the option selected, CT will usually only let us add viapoints on recognised routes - because that's what we said we wanted. 

On such a relatively short journey the solution is to select 'Any' or 'Paved' instead of 'Routes', set start and end points, let CT calculate the route, add viapoints and drag to EV1 (to keep CT on it) and simply add any 'off-route' viapoints as you like. 

A quick check suggests that CT will follow the EV1 after Waterford but needs to be coaxed to do it between Fethard & Waterford. 

On longer journeys you'll need to decide if you want to stick 100% to the official route or modify CT's suggestions. 

As an aside, I am not a fan of 'official' routes as anything more than just an outline. One of the reasons that 'Routes' was added as an option was because CT often does not choose official routes. There are normally good reasons for that! :-)

Sorry for the confusion - it is the Coastal route at the point I was trying to change. Anyhow I switched to Any and then dragged the route back to where I wanted it to be. Relatively simple - thanks. 

'I am not a fan of 'official' routes as anything more than just an outline' I agree, I only selected that in an attempt to force the route onto the coast. But then I couldn't adjust it.