Hi,
My lot have been a bit like that recently. They seem to go through phases where they eat all their pellet food and veg, and sometimes they only eat their veg (at turbo munch speed) and hay. They're the same with water (although they sometimes tend to play with the bottle spout and let the water leak out all over them).
As long as they seem otherwise ok (not losing weight or showing any early signs of illness) then they should be fine. It could be worth mixing a bit of different food like a museli mix with their pellets to try and get some interest, or skip a veg portion and see if they eat their pellet food then (you might need to bribe them with a bit of extra veg later to keep the peace!).
If they've not picked up within a day or two, I would get them a check up just to be safe.