Hi @centralflorida, that seems a high dosage of prednisone for PMR - it's usually about 20 mg. I had symptoms of PMR/GCA for a year before diagnosis and was prescribed 40 mg of prednisone to start with a 5 mg taper every two weeks. It did give me insomnia.
I was off prednisone a year and a half, then had a relapse of GCA and started taking 40 mg, but it did not disrupt my sleep this time around. Now I'm down to 5 mg.
Best to see a rheumatologist as soon as you can.