Very unlikely to be the wrong fluid. Hope have been in this game longer than anyone else. I’d be very surprised if a bike shop made a mistake like that. If they did use mineral oil rather than brake fluid, you’ll know soon enough as seals swell and you get nothing at all from the brakes.
Unlikely a bleed will do anything if you get the brakes working, just later in the stroke.
When I’ve had this in the past, it was cured by a change of seal. It could either be that the caliper seals are letting the pistons slip all the way back or the first seal on the master piston has failed and it’s the second seal doing the work.
Is it both levers or just one?
kcal, that fixing only adjusts the lever reach although it could be that the levers are just wound in too far. Wind it all the way out and see how things work.