Levain failure - seeking a solution

Hi, I started my levain using the Tartine method (1 T. starter), and while my starter seemed very active (7 hours after feeding), for some reason the levain is not developing.  It has been six hours, and it usually works in much less time.  I had it in a Brod & Taylor proofer at 77 degrees. Meanwhile, I have had an autolyse going for over two hours now, with 900 grams flour.  Should I just be patient or try to make a yeast bread out of the autolysed flour?!  Thanks!