200amp disconnect on side of house tripping

[LISHAJI]

I would think that the inside breaker would be quicker to trip on overload due to a higher ambient temp. Is there a loose connection on the outside breaker, possibly a defective breaker.

I would not say overload, maybe SC. The fixed Instantaneous Trip for a 60A is 800-1450 and for a 200A is 1200-2400A. Rather then betting on the overlap, I would check if the 60A breaker is defective.