What could cause lower back pain when sleeping? when i get up ok., i have no pain when seated, but when i get up, my right buttock hurts when i first put weight on that leg, then eases up after a few steps. no pain down the leg. only right hip?

The hip pain is due to the muscular tightness with prolonged sitting. There is nothing wrong with the hip joint or nerve. You need to avoid prolonged sitting and you should exercise your hip muscles more. The back pain with sleeping is also from the paraspinal muscles, use a firm mattress and exercise your back will alleviate the symptom.

Would certainly wonder about the integrity of the right sacroiliac joint, and possibly the right hip labrum. Your pattern does seem consistent with arthritic issues, which typically improve as joint is used through range of motion. A physical therapist could help. Stretching over hamstrings should be done daily.