That's an interesting picture, the leaves don't look too bad. If it isn't from overwatering it might be that they need a bit of protection after being re-planted into the ground. I think I would rig something up to shade them for a few days, no direct sun in other words, they may snap out of it. I have a neighbor who puts cut off bleach bottles on everything she puts in the ground because she worries about the effect direct sun might have on new plants. I do it myself sometimes, it can be a good idea and our spring weather here is likely a lot cooler than yours. Good luck!

Are those in full sun? The green-leaved, pink-flowered wax begonias do better in shade. The red-leaved (burgundy-leaved), pink or white-flowered ones do fine in full sun.