What is the shell length?
Sometimes the little ones under two inches can be a little shy, and wary of new people.
I wouldn't handle the turtle right now unless it's absolutely necessary (like it flips itself on it's back, or the tank needs to be cleaned immediately). UVB would probably make it more active. For now, it might feel very safe in that one spot it stays in. When my turtles were new to the house they had their special places they spent a lot of time in, but they are older now and don't do that anymore.
Typhoon- Female RES/Mississippi Map Turtle, 5 1/2 inches
Hurricane- Female RES, 5 1/4 inches
Sadie- Female RES, 8 inches
Jenny- Female, orange tabby
Spike- Male, Egyptian Mau
Sophie- Colombian red tail boa, 3 ft approx.