Sloth Arduino robot - power from USB, no power from 9V battery

My son is working on assembling his Sloth Arduino robot kit (maybe a slightly older version, just takes a regular 9V, not a rechargeable). He was having trouble with it only powering on when connected to USB, but not when connected to just a 9V battery.

I saw a note on the SunFounder website somewhere about possible improper battery connections but that appears to be wired correctly. I have used my multimeter to verify 9V power gets across the power switch when it’s turned on. I can also read 9V on the small screw terminals that I believe are an alternate power terminal.

However, the Arduino board never turns on, and I can’t read power on the Arduino board’s pins (I expected GND and Vin to show power?). It also looked like the LM2596 is used to step-down the power from the 9V to 5V for the board (and probably servos), and I read no voltage reaching the Vin pin on the LM2596. Something seems incorrect, possibly in the main board, or perhaps something is wrong on the Arduino board, if I’m mistaken on the use of the LM2596. Either way, some assistance is needed… has anyone seen this before, or know what we can do to get this working?

Thank you!

Can you meet the problem, do a video for us, or provide key pictures to us, so that we can easily analyze the problem.
Shooting information, as you said the situation can be shot.