Battery powered Seeeduino 4.2 does not run sketch

Hello. Some guidance please. I have Seeeduino 4.2, and have uploaded a new sketch, which runs when connected to USB power, is persistent in memory, and runs immediately upon connection. But the sketch does not run when powered by 9v battery ?? The display lights up, but no program. I am using the Adafruit 1947 display shield. How come the battery power doesn’t run the sketch? Thx