Grows in front, but not in back, but has the same soil. Does it have the same water and fertilizer? Most likely cause is a shade situation is slowing it down. Shade combined with high soil temperature kills roots. Fastest turf loss is in August.
Is this tall fescue? Have you done a soil test?
Is it weaker when the sunlight is low and stronger where there are more hours of sunlight per day? Remember we have fewer hours of sunlight in the fall.
I think you are holding your phone upside down.