Are you possitive that you temp gauge and hygrometer are correct? The normal way to bring them out of hibernation is to gradually raise the temps and humidity up over a span of a week or 2 until the frogs emerge and begin to awaken. If the temps are already where they need to be then I don't know. You may have to dig them up and inspect the frogs. See if they're active or actually hibernating. If they've been under that long than the reason why they look of normal weight is due to water weight. What is the night time temps you keep them at and what type of night bulb? How many watts are your bulbs and how moist is your soil for them? Do you de-chlorinate your frogs water? I sence stress being an issue possibly. Do you have 3 sides of the tanks covered with some sort of background.