I just went down to check on them and one of them is right under the hot light and eating the grass that is growing off the floor! This is the first time I have ever seen this. The other one is in the same spot from last night.
That is a good sign.
About the UV. What brand and type bulb do you have? The regular 10.0 bulbs offer very little UV and they need to be no more than 10-12" away from the tortoise to do anything at all. No UV at all will pass through the plexi. So have your tortoises had no UV for all this time?
The one might still be sitting over in the other side because it knows it should not be in the territory of the other one and its trying to keep a low profile. You need to separate them.