Basically, Gemuse, the plants are too small for the pots. At the moment, what they are doing, is trying to fill the pot with roots at the expense of the topgrowth. You now need to be patient and hope they recover.
with all the hot weather, the leaves may be 'burning' as tempretures in the conservitory may be up to 10 - 15 degrees higher than outside.
Try moving them to a cooler but well lit spot.