Did anything happen between flight 1 and flight 2 which could have damaged anything on the drone?
When you power on your Starling 2, do you see blue lights blinking on the ESC? You can see the description of the expected behavior here : https://docs.modalai.com/voxl-escs/faq/#q-what-is-the-behavior-of-the-four-blue-on-board-leds. In the ESC datasheet (https://docs.modalai.com/voxl-mini-esc-datasheet/) you can see which side the LEDs are located and one of them is labeled, you should be able to spot the other three next to the each MCU.
Do you hear a tone that the ESC typically makes (using motors) when the power is applied?
Please check the integrity of the UART cable that connects the ESC to VOXL2.
Alex