Problems with a puppy?

[Big River Beagles S]

My friend has a pup that is a little over a yr old been started for about 2 months. She runs great with another dog or a pack.I have seen here run the front against some pretty solid dogs one on one and a checking machine. I have seen her solo a rabbit when the other dogs get on a split and do a fair job but needs some help with line control and needs to settle down a little. So he was going to try to solo her some she needs it. Well he takes her out by herself and has tried it 3 or 4 times and the pup won't do anything. You would swear she wasn't even started walk her accross a rabbit track and she will get happy tailed but won't go. She acts very timid and scared of everything. This pup wasn't at all this way before he took her to the starting pen she hunted good by herself just was having trouble finding rabbits so took her to the pen. I took her home with me monday and ran her with my pup for a little bit and she hunts and runs hard with a lot of desire and no quit. So I took her to a place last night loaded with rabbits by herself walked her around for about an hour couldn't get her to do anything. She acted scared to death of everything and acted like she never seen a rabbit before. So I tried something I went home got my old dog and put her on a leash and walked her around with the pup and she took right off on a rabbit. She ran it a full circle and stayed out looking for it when she lost it for 15 minutes. So anyone have any ideas what could have caused this. Scott