Z740 cannot focus on long-distance indoor shots

All my long-distance indoor photos are ALWAYS out of focus. Pics of kids concerts, graduations, etc are catastrophically blurry. The camera insists that I "open the flash" even for pictures ~100' away. when flash is open, pictures appear to be reasonably in focus, although obviously extremely dark. Disabling the flash does not result in any better results

Outdoor shots have breathtaking clarity, no matter how close or far away.